Climate and monthly weather forecastSisters, OR
Climate and monthly weather forecast
The climate of Sisters
Nestled in central Oregon, USA, the town of Sisters is host to a Mediterranean, warm summer climate, identified by the Köppen climate classification as "Csb". This predominating climate influences the overall weather pattern in Sisters, fostering a marked contrast between warmer, wetter winter months and a drier summer season.Temperatures consistently fluctuate over a range, with high temperatures spanning from a brisk 36.5°F (2.5°C) in the coolest month of December, to a warm 78.8°F (26°C) peak experienced in July. Low temperatures show a similar pattern, displaying a range from 24.8°F (-4°C) in December to 50.7°F (10.4°C) in August. Relative humidity shows inversely proportioned changes, with the driest months corresponding to the warmest temperatures, reaching a yearly low of 53% during July and August.
It is noteworthy that rainfall here is more abundant during colder months, with a maximal monthly average rainfall of 3.31" (84mm) in January decreasing to mere 0.35" (9mm) in July. Snowfall is consistently seen from December to April, with a magnificent peak of 13.74" (349mm) in February. Days of daylight are longest in June, resulting in approximately 15.5 hours of daylight. Sunshine hours, on the other hand, reach a yearly maximum of 12 in July.
The best time to visit Sisters
With information regarding climate, it becomes apparent that the best time to visit Sisters hinges on the preference of activities for the visitor. During July till September, average high temperatures hover around 69.8°F (21°C) to 78.8°F (26°C) with a reduced rainfall, averaging between 0.35" (9mm) to 1.02" (26mm) monthly. This provides a golden opportunity for those intending to explore outdoor activities such as hiking or camping.A considerable number of sunshine days in the months of July and August, reaching up to 23.3 days, coupled with an ideal UV index of 6 in July, provides perfect conditions for sun seekers. Wind speeds during these months also moderate, with the average wind speed of around 4.9mph (7.9km/h) in July and gust peaks reducing to approximately 7.5mph (12.1km/h), providing more comfortable conditions for outdoor activities.
The worst time to visit Sisters
The travel to Sisters might feel less enjoyable during its colder and wetter months. From late autumn to early spring, specifically from November to March, weather conditions might dissuade certain travelers. During these months average high temperatures loom only around 36.5°F (2.5°C) to 49.8°F (9.9°C), accompanied by high precipitation, reaching up to a peak of 3.31" (84mm) in January.In addition, those months are host to the highest snowfall, noting up to 13.74" (349mm) in February. In December, shorter daylight hours (8.9 hours a day) and more cloud coverage (49%) might make outings less appealing for some.
Spring weather in Sisters
Spring in Sisters, taking place from March through May, witnesses a gradual increase in temperature reaching up to 60.1°F (15.6°C) in May. Early spring experiences a blooming of nature as the snow starts to melt, with the snowfall quickly reducing from 10.67" (271mm) in March to virtually zero by May. The precipitation averages from 2.68" (68mm) in March to 2.01" (51mm) in May.Meanwhile, daylight begins to stretch from 12 to 14.8 hours from March to May. April witnesses a jump in sunshine hours to around 9.6 hours a day. The season is generally moderate with few extremes, making it a time of welcome relief from the harsh winter.
Summer weather in Sisters
The summer in Sisters monopolizes the driest and warmest conditions of the year. Temperature highs average from 67.5°F (19.7°C) in June to around 78.8°F (26°C) in July, before gradually decreasing in August. Accompanied by limited precipitation ranging from 1.1" (28mm) in June to 0.51" (13mm) in August, these months make for the perfect time to bask in the glory of the sun.Sunshine hours peak in July with 12 hours of daylight, granting the area a lively sunlit charm. The UV index also reaches its yearly high during this period, hitting the mark of 6, signaling the necessity of sunscreen for outdoor enthusiasts.
Autumn weather in Sisters
Autumn turning the leaf from September to November initiates a decrease in daily high temperatures, averaging from 69.8°F (21°C) in September to a cooler 44.2°F (6.8°C) in November. Autumn witnesses an uptick in the amount of rainfall, rising from 1.02" (26mm) in September to 2.2" (56mm) by November.Daylight hours in this season take a dip, reducing to an average of 11 hours in October and further to 9.6 hours in November. However, the weather remains generally pleasant and the changing color of the leaves provides a picturesque setting, attracting many to experience this beauty.
Winter weather in Sisters
Winter in Sisters runs from December to February, where cold temperatures and snowfall become daily phenomena. The monthly high averages from 36.5°F (2.5°C) in December to a marginally higher 42.8°F (6°C) in February, with the lowest temperatures delving down to 24.8°F (-4°C) in December.Snowfall becomes a dominant feature of this season, displaying monthly peaks of 12.09" (307mm) in December and a significant 13.74" (349mm) in February. The shorter daylight hours, reaching the lowest of 8.9 in December, coupled with the forecasted cloud coverage of around 49% throughout winter, lend to a particularly chilly ambiance during these months. However, the winter landscape does provide its own unique beauty and draws snow sport enthusiasts to embrace the adventurous season.
Weather in January
Frugality in daylight is the hallmark of January weather in Sisters, Oregon, as the duration of sunshine records its yearly minimum. Temperature values usually stay clustered in the lower degrees, often sliding down to the lows of 26.6°F (-3°C) at night. Weather in January »Weather in February
February carries an unmissable imprint of January's climate. The temperature retains its unwavering devotion to cold and snugs at a low of 27.1°F (-2.7°C). An exemplar of consistency, such weather encompasses snow-cloaked paths and retains a good deal of pressure, as might be expected during the grasp of winter. Weather in February »Weather in March
March signals a turn in Oregon’s Sister's weather with the transition into spring. Subtle warming trends begin to elbow their way into the chilling residue of winter, raising the temperature to around 42.8°F (6°C). Weather patterns commence shifting their stance towards rainfall, nudging away the snow. Weather in March »Weather in April
In Sisters, Oregon, April is the month where spring finally comes into its own. The mercury spurts ahead to about 49.8°F (9.9°C), making way for a more hospitable climate. Unsurprisingly, the city welcomes more sunshine, allowing residents to bask in the warmth of extended daylight hours. Weather in April »Weather in May
May brings about the first glimpses of summer and greets Sisters, Oregon with more far-reaching warmth. The high temperature break-outs register 60.1°F (15.6°C), rendering the air noticeably warmer than preceding months. The city witnesses less rainfall but benefits from increased sunlight hours. Weather in May »Weather in June
June projects a firm stride towards summer in Sisters, Oregon. An upward swing in temperature continues, recording a scorching high of 67.5°F (19.7°C). An overture of summer's arrival, this time spell transmits more sunlit hours. Rainfall, although not absent, certainly draws back. Weather in June »Weather in July
July asserts itself as the peak of the summer season in Sisters, Oregon, taking the temperature to an annual maximum of 78.8°F (26°C). This month proudly presents an exuberant display of sunshine with longer daylight hours. Given the high temperature and low rainfall, July forms the driest period of the year. Weather in July »Weather in August
The peak of summer reaches a plateau in August. Sisters upholds a high-end temperature around a stable 78.4°F (25.8°C), maintaining July's warmth. Concurrently, the rainfall index inches slightly upwards as the month progresses. Weather in August »Weather in September
As Sisters, Oregon slides into September, summer gently hands over the baton to autumn. A cooler breeze commences, registering a high of 69.8°F (21°C), a marked dip from August's high. September harbors a modestly raised rainfall index, often featuring scattered showers. Weather in September »Weather in October
October in Sisters, Oregon recognizes the onset of a clear autumnal phase. The temperature comfortably nests at a cooler 55.8°F (13.2°C). The month characteristically dots the weather map with a smattering of rainfall events. Wind speed picks up the pace, claiming dominance after the lull of summer. Weather in October »Weather in November
November gazes upon the approaching winter with temperature values often sliding back to a lower 44.2°F (6.8°C) in Sisters, Oregon. Rainfall prevails over the minimalistic warfare of snow showers, a prelude to the winter months ahead. Weather in November »Weather in December
As December rolls in, Sisters, Oregon finally gives in to winter’s clasp. The mercury dips further to an average low of 36.5°F (2.5°C). The snowfall comes to the party uninvited and often lays the first instances of a white blanket over the city. Weather in December »Updated: Jul 7, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
January is the month with the most rainfall. Rain falls for 12.8 days and accumulates 3.31" (84mm) of precipitation.
Throughout the year, there are 142.1 rainfall days, and 22.87" (581mm) of precipitation is accumulated.
Months with snowfall are January through May, September through December.
In Sisters, during the entire year, snow falls for 70.7 days and aggregates up to 60.04" (1525mm) of snow.
The month with the most snowfall is February, when snow falls for 12.6 days and typically aggregates up to 13.74" (349mm) of snow.
The month with the lowest UV index is February, with an average maximum UV index of 1.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.
June through August are months without snowfall.
With an average of 15h and 30min of daylight, June has the longest days of the year.
July is the month that records the highest temperatures, with averages ranging from a high of 78.8°F (26°C) to a low of 49.6°F (9.8°C).
The months with the lowest humidity are July and August, with an average relative humidity of 53%.
July is the month with the least rainfall in Sisters. Rain falls for 5 days and accumulates 0.35" (9mm) of precipitation.
The month with the most sunshine is July, with an average of 12h of sunshine.
The month with the highest UV index in Sisters, Oregon, is July, with an average maximum UV index of 6.
Sisters's coldest temperatures are experienced in December, with average high temperatures of 36.5°F (2.5°C) and lows of 24.8°F (-4°C).
December is the most humid month, with an average relative humidity of 84%.
The month with the shortest days in Sisters is December, with an average of 8h and 54min of daylight.
With an average of 5.1h of sunshine, December has the least sunshine of the year.
Average temperature
Sisters, OR
The warmest month (with the highest average high temperature) is July (78.8°F).
The month with the lowest average high temperature is December (36.5°F).
The month with the highest average low temperature is August (50.7°F).
The coldest month (with the lowest average low temperature) is December (24.8°F).
Average pressure
Sisters, OR
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.1"Hg - Average pressure in March:
30.05"Hg - Average pressure in April:
30.05"Hg - Average pressure in May:
30"Hg - Average pressure in June:
30"Hg
- Average pressure in July:
30"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30"Hg - Average pressure in October:
30.06"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.98"Hg).
Average wind speed
Sisters, OR
- Average wind speed in January:
5.8mph - Average wind speed in February:
6.1mph - Average wind speed in March:
6mph - Average wind speed in April:
6mph - Average wind speed in May:
5.5mph - Average wind speed in June:
5.5mph
- Average wind speed in July:
4.9mph - Average wind speed in August:
4.8mph - Average wind speed in September:
4.8mph - Average wind speed in October:
5.2mph - Average wind speed in November:
5.9mph - Average wind speed in December:
5.8mph
The windiest month (with the highest average wind speed) is February (6.1mph).
The calmest months (with the lowest average wind speed) are August and September (4.8mph).
Average humidity
Sisters, OR
The month with the highest relative humidity is December (84%).
The months with the lowest relative humidity are July and August (53%).
Average rainfall
Sisters, OR
- Average rainfall in January:
3.31" - Average rainfall in February:
2.8" - Average rainfall in March:
2.68" - Average rainfall in April:
2.01" - Average rainfall in May:
2.01" - Average rainfall in June:
1.1"
- Average rainfall in July:
0.35" - Average rainfall in August:
0.51" - Average rainfall in September:
1.02" - Average rainfall in October:
1.73" - Average rainfall in November:
2.2" - Average rainfall in December:
3.15"
The wettest month (with the highest rainfall) is January (3.31").
The driest month (with the least rainfall) is July (0.35").
Average rainfall days
Sisters, OR
- Average rainfall days in January:
12.8 days - Average rainfall days in February:
12.2 days - Average rainfall days in March:
16.9 days - Average rainfall days in April:
15.9 days - Average rainfall days in May:
15 days - Average rainfall days in June:
11.4 days
- Average rainfall days in July:
5 days - Average rainfall days in August:
6.1 days - Average rainfall days in September:
8.1 days - Average rainfall days in October:
12.7 days - Average rainfall days in November:
13 days - Average rainfall days in December:
13 days
The month with the highest number of rainy days is March (16.9 days).
The month with the least rainy days is July (5 days).
Average snowfall
Sisters, OR
- Average snowfall in January:
12.09" - Average snowfall in February:
13.74" - Average snowfall in March:
10.67" - Average snowfall in April:
3.39" - Average snowfall in May:
0.63" - Average snowfall in June:
0"
The month with the highest snowfall is February (13.74").
The months with the least snowfall are June, July and August (0").
Average snowfall days
Sisters, OR
- Average snowfall days in January:
11.2 days - Average snowfall days in February:
12.6 days - Average snowfall days in March:
13.1 days - Average snowfall days in April:
7.2 days - Average snowfall days in May:
2.4 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0.3 days - Average snowfall days in October:
1.4 days - Average snowfall days in November:
7.8 days - Average snowfall days in December:
14.7 days
The month with the highest number of snowfall days is December (14.7 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight / Average sunshine
Sisters, OR
- Average daylight in January:
9h and 18min - Average daylight in February:
10h and 30min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 30min - Average daylight in May:
14h and 48min - Average daylight in June:
15h and 30min
- Average daylight in July:
15h and 6min - Average daylight in August:
14h and 0min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 36min - Average daylight in December:
8h and 54min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in January:
5h and 12min - Average sunshine in February:
5h and 18min - Average sunshine in March:
7h and 6min - Average sunshine in April:
9h and 36min - Average sunshine in May:
10h and 36min - Average sunshine in June:
11h and 12min
- Average sunshine in July:
12h and 0min - Average sunshine in August:
11h and 48min - Average sunshine in September:
10h and 36min - Average sunshine in October:
6h and 30min - Average sunshine in November:
6h and 6min - Average sunshine in December:
5h and 6min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days
Sisters, OR
- Average sunshine days in January:
12.3 days - Average sunshine days in February:
9 days - Average sunshine days in March:
8.1 days - Average sunshine days in April:
9.3 days - Average sunshine days in May:
11.9 days - Average sunshine days in June:
15.8 days
- Average sunshine days in July:
23.3 days - Average sunshine days in August:
21.8 days - Average sunshine days in September:
18.9 days - Average sunshine days in October:
15.7 days - Average sunshine days in November:
11.8 days - Average sunshine days in December:
11.1 days
The month with the most sunshine days is July (23.3 days).
The month with the least sunshine days is March (8.1 days).
Average UV index
Sisters, OR
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover
Sisters, OR
The months with the most cloud cover are January, February, March and December (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility
Sisters, OR
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
