Climate and monthly weather forecastKeizer, OR
Climate and monthly weather forecast
The climate of Keizer
Recognized by the Köppen Climate Classification system as a 'Csb' climate, Keizer, Oregon, USA, experiences a type of Mediterranean Climate, known for its warm summers. Documented history of weather patterns showcases overall a mild climate throughout the year, imbued with slight variations in weather conditions.The average high temperature peaks in July at 82°F (27.8°C), before receding gradually towards the year-end to 45.5°F (7.5°C) in December. Conversely, conditions are coldest in the first month, January, seeing a low average temperature of 35.2°F (1.8°C), warming up slowly reaching a high of 54.1°F (12.3°C) in August.
Relative humidity follows a symmetrical trend, fluctuating from a high of 86% in January and February, dropping down to 65% in August, and climbing back to 86% by year-end. Keizer experiences more rainfall from November to March, with December recording the highest showers of 3.94" (100mm). Rainfall gradually diminishes as the year progresses, with July and August witnessing the least amount of rainfall: a minimum of 0.28" (7mm).
Interestingly, the city sees human-dwarfing amounts of snowfall mainly from November to March, with negligible amounts otherwise. This fluctuation in snowfall closely aligns with the daily hours of daylight reported, the longest being from May to July, approximately ranging from 14.9 hours to 15.6 hours.
Between the months of June and August, there lies a significant increase in daylight hours and sunshine hours, reducing the frequency of cloud cover. This seasonal contrast is primarily driven by the Earth’s tilt and orbit around the sun.
The best time to visit Keizer
With the Mediterranean climate offering balmy summers, the most recommended time to visit Keizer ranges from June to August. These summer months offer an ideal window to experience the warm hospitality of the city under the abundant sunshine, receiving up to 9.5 to 11 sunlight hours per day. Alongside, favorable conditions include the lowest relative humidity ranging from 67% to 65%, least rainfall averaging 0.28" (7mm) to 0.31" (8mm), and overall longer daylight hours.The worst time to visit Keizer
Due to the cold snaps, reduced sunlight, and increased levels of snow and rain, the months between November and March make for the least favorable times to visit Keizer. A low UV index around 2, lower visibility, 5 miles, and a peak average rainfall of 3.94" (100mm) in December make it challenging for navigation and sightseeing around the city.Spring weather in Keizer
Spring arrives in Keizer from March until May. Throughout this period, Keizerites witness an upswing in temperature, rising from an average low of 37.4°F (3°C) in March to 42.8°F (6°C) in May. Similarly, high temperatures also escalate from 52.9°F (11.6°C) in March to 66.7°F (19.3°C) in May. Spring months observe a relative reduction in the volume of rainfall, with the month of May recording the lowest average rainfall of spring, at 1.46" (37mm). This season is marked by an increase in daylight hours, from 12 hours in March to 14.9 hours in May.Summer weather in Keizer
Stretching from June to August, summer in Keizer offers its residents an extended period of warmth and longer daylight hours, reaching up to 15.6 hours in June. Average high temperatures scale up to 82°F (27.8°C) in the month of July offering perfect conditions for outdoor activities. July and August are the driest months with minor rainfall observed, a minimal 0.28" (7mm) in July and slightly more, 0.31" (8mm) in August.Autumn weather in Keizer
Autumn in Keizer, spanning from September through November, introduces a decrease in average high temperatures, ranging from 74.7°F (23.7°C) in September to 51.8°F (11°C) in November. Rainfall begins to increase from 1.22" (31mm) in September to 2.72" (69mm) in November and days start getting shorter with daylight hours decreasing from 12.5 hours in September to 9.6 hours in November.Winter weather in Keizer
Winters in Keizer extend from December to February. During these months, average high temperatures can fall to 45.5°F (7.5°C) in December with conditions somewhat improving to 48.7°F (9.3°C) in February. Winter months are paired with increased precipitation, with December recording the maximum average rainfall of 3.94" (100mm). The daylight hours shrink to their smallest, with average daily light only lasting for 8.8 hours in December.Weather in January
January weather in Keizer, Oregon is characterized by a substantial amount of rainfall and limited daylight. Corners of the city are covered in a light dusting of snow for about 0.9 days of the month with a snowfall of 0.43" (11mm). Weather in January »Weather in February
February heralds a slight increase in temperatures in Keizer, Oregon, although it still remains firmly in the winter season. The month sees a bit more snowfall compared to January, with a total of 1.18" (30mm) spread across 1.8 days. Weather in February »Weather in March
March introduces a slight shift in the weather pattern in Keizer, Oregon, with temperatures rising a little more, and the frequency of rain increasing significantly. The rainfall is a notable 2.99" (76mm), the third highest in the year, making it one of the wettest months on record. Weather in March »Weather in April
April marks the departure from more frigid temperatures, and commences the arrival of the idyllic spring weather in Keizer, Oregon. Rainfall decreases to 2.32" (59mm), signalling a push towards drier conditions. The climate is typified by a blend of gentle breezes, balmy afternoons, and mild, calm nights. Weather in April »Weather in May
May ushers in a noticeable improvement in the atmospheric conditions in Keizer, Oregon, with the advent of the warmer, drier weather that precedes summer. Rainfall diminishes to 1.46" (37mm), indicating the transition from the rainy season to one of more dryness and warmth. Weather in May »Weather in June
June is seen as the official commencement of summer in Keizer, Oregon, signified by marked increases in both temperature and hours of sunlight. The rainfall shrinks to 1.02" (26mm), making it the driest month since the onset of the new year. Weather in June »Weather in July
July is famously the hottest month in Keizer, Oregon, offering amiable summer weather that's perfect for vacationing or cooling off by the refreshing river. This month records the highest temperature of 80.8°F (27.1°C) and a significant dip in rainfall to 0.28" (7mm). Weather in July »Weather in August
In Keizer, Oregon, August carries forward the summer's heat from July, but with slightly cooler temperatures. Even though it's the peak of summer, the rainfall is minimal at 0.31" (8mm), so conditions remain arid. This period signifies the last stretch of the summer season. Weather in August »Weather in September
September hosts a shift from the warm summer climate to a cooler autumn atmosphere in Keizer, Oregon. It receives the first sign of significant rainfall since the onset of summer, standing at 1.22" (31mm). The breezy coolness of the upcoming fall makes its presence known. Weather in September »Weather in October
October delivers a fully-fledged autumnal climate in Keizer, Oregon, characterized by cool breezes and colorful foliage. The rainfall picks up the pace, registering at a noticeable 2.4" (61mm). The leaves start to turn into shades of orange, yellow, and red, aligning with the archetypal autumn appearance. Weather in October »Weather in November
November unfurls an amalgamation of late autumn and early winter weather in Keizer, Oregon. With the second-highest average temperature drop of the year and an increase in rainfall to 2.72" (69mm), November ushers in winter. A stark contrast between the falling leaves of November and the arrival of winter creates a mosaic of seasons. Weather in November »Weather in December
December culminates the year with classic winter weather in Keizer, Oregon. This month registers the highest rainfall at 3.94" (100mm), signaling the onset of the rainy winter season. The air is filled with a constant chill, the skies often blanketed by pale gray clouds. Weather in December »Updated: Jun 4, 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
The months with the highest humidity are January, February and December, with an average relative humidity of 86%.
In Keizer, during the entire year, the rain falls for 162.5 days and collects up to 25.08" (637mm) of precipitation.
January through March, November and December are months with snowfall.
Throughout the year, there are 4.7 snowfall days, and 2.48" (63mm) of snow is accumulated.
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Keizer.
The month with the most snowfall is February, when snow falls for 1.8 days and typically aggregates up to 1.18" (30mm) of snow.
February has the least sunshine of the year, with an average of 4.2h of sunshine.
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.
April through October are months without snowfall.
June has the longest days of the year, with an average of 15h and 36min of daylight.
July is the month with the least rainfall in Keizer. Rain falls for 3.9 days and accumulates 0.28" (7mm) of precipitation.
With an average maximum UV index of 6, July is the month with the highest UV index.
August, characterized by an average high temperature of 82°F (27.8°C) and a low temperature of 54.1°F (12.3°C), is generally the warmest month.
The least humid month is August, with an average relative humidity of 65%.
With an average of 11h of sunshine, August has the most sunshine of the year.
In Keizer, the average lowest temperatures are observed in December, with a high of 45.5°F (7.5°C) and a low of 34.5°F (1.4°C).
The month with the most rainfall in Keizer is December, when the rain falls for 18.3 days and typically aggregates up to 3.94" (100mm) of precipitation.
December has the shortest days of the year, with an average of 8h and 48min of daylight.
Average temperature
Keizer, OR
The warmest month (with the highest average high temperature) is August (82°F).
The month with the lowest average high temperature is December (45.5°F).
The month with the highest average low temperature is August (54.1°F).
The coldest month (with the lowest average low temperature) is December (34.5°F).
Average pressure
Keizer, OR
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.08"Hg - Average pressure in March:
30.04"Hg - Average pressure in April:
30.07"Hg - Average pressure in May:
30.04"Hg - Average pressure in June:
30.04"Hg
- Average pressure in July:
30.04"Hg - Average pressure in August:
30.01"Hg - Average pressure in September:
30.01"Hg - Average pressure in October:
30.05"Hg - Average pressure in November:
30.06"Hg - Average pressure in December:
30.1"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed
Keizer, OR
- Average wind speed in January:
5.5mph - Average wind speed in February:
5.4mph - Average wind speed in March:
5.5mph - Average wind speed in April:
5.1mph - Average wind speed in May:
4.5mph - Average wind speed in June:
4.4mph
- Average wind speed in July:
4.4mph - Average wind speed in August:
4.2mph - Average wind speed in September:
4.4mph - Average wind speed in October:
4.9mph - Average wind speed in November:
5.5mph - Average wind speed in December:
5.3mph
The windiest months (with the highest average wind speed) are January, March and November (5.5mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity
Keizer, OR
The months with the highest relative humidity are January, February and December (86%).
The month with the lowest relative humidity is August (65%).
Average rainfall
Keizer, OR
- Average rainfall in January:
3.66" - Average rainfall in February:
2.76" - Average rainfall in March:
2.99" - Average rainfall in April:
2.32" - Average rainfall in May:
1.46" - Average rainfall in June:
1.02"
- Average rainfall in July:
0.28" - Average rainfall in August:
0.31" - Average rainfall in September:
1.22" - Average rainfall in October:
2.4" - Average rainfall in November:
2.72" - Average rainfall in December:
3.94"
The wettest month (with the highest rainfall) is December (3.94").
The driest month (with the least rainfall) is July (0.28").
Average rainfall days
Keizer, OR
- Average rainfall days in January:
17.1 days - Average rainfall days in February:
16.3 days - Average rainfall days in March:
19.6 days - Average rainfall days in April:
17.7 days - Average rainfall days in May:
13.4 days - Average rainfall days in June:
10.8 days
- Average rainfall days in July:
3.9 days - Average rainfall days in August:
4 days - Average rainfall days in September:
8.9 days - Average rainfall days in October:
15.1 days - Average rainfall days in November:
17.4 days - Average rainfall days in December:
18.3 days
The month with the highest number of rainy days is March (19.6 days).
The month with the least rainy days is July (3.9 days).
Average snowfall
Keizer, OR
The month with the highest snowfall is February (1.18").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days
Keizer, OR
- Average snowfall days in January:
0.9 days - Average snowfall days in February:
1.8 days - Average snowfall days in March:
1.2 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 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 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0.2 days - Average snowfall days in December:
0.6 days
The month with the highest number of snowfall days is February (1.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Keizer, OR
- Average daylight in January:
9h and 12min - 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 54min - Average daylight in June:
15h and 36min
- Average daylight in July:
15h and 12min - Average daylight in August:
14h and 0min - Average daylight in September:
12h and 30min - Average daylight in October:
10h and 54min - Average daylight in November:
9h and 36min - Average daylight in December:
8h and 48min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in January:
4h and 18min - Average sunshine in February:
4h and 12min - Average sunshine in March:
5h and 48min - Average sunshine in April:
7h and 18min - Average sunshine in May:
8h and 36min - Average sunshine in June:
9h and 30min
- Average sunshine in July:
10h and 54min - Average sunshine in August:
11h and 0min - Average sunshine in September:
9h and 24min - Average sunshine in October:
5h and 30min - Average sunshine in November:
4h and 48min - Average sunshine in December:
4h and 18min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days
Keizer, OR
- Average sunshine days in January:
12.4 days - Average sunshine days in February:
9.3 days - Average sunshine days in March:
8.8 days - Average sunshine days in April:
10.3 days - Average sunshine days in May:
16.3 days - Average sunshine days in June:
17.2 days
- Average sunshine days in July:
26.3 days - Average sunshine days in August:
25.2 days - Average sunshine days in September:
20 days - Average sunshine days in October:
14.8 days - Average sunshine days in November:
11.3 days - Average sunshine days in December:
10.6 days
The month with the most sunshine days is July (26.3 days).
The month with the least sunshine days is March (8.8 days).
Average UV index
Keizer, OR
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover
Keizer, OR
The month with the most cloud cover is February (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 21).
Average visibility
Keizer, OR
The months with the highest visibility are July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, May, June, October, November and December (5mi).
