Climate and monthly weather forecastSammamish, WA
Climate and monthly weather forecast
The climate of Sammamish
Sammamish, Washington, USA, falls under the Csb category of the Köppen climate classification, indicating a warm summer Mediterranean climate. Geographically perched in a region of moderate climate characteristics, the city experiences mild, aloof summers and moderately cold winters, resulting in a balanced Mediterranean weather distribution throughout the year.Analyzing the yearly climatological pattern in Sammamish, it becomes evident that the average high temperature escalates from 44.1°F (6.7°C) in January to a peak of 76.5°F (24.7°C) in August. In contrast, the average low temperature follows a similar trajectory, rising from 34.3°F (1.3°C) in January to 52.2°F (11.2°C) in August.
Relative humidity in Sammamish declines from 85% in January to 70% in July, followed by a gradual rise towards the closing months of the year. The pattern of rainfall reveals a notable precipitative peak of 1.85" (47mm) in December. It is noteworthy to mention that rainfall is present with an annual average of between 10 to 10.5 days per month from June to October, offering Sammamish a unique dry summer, a significant peculiarity of Csb Mediterranean climates.
The best time to visit Sammamish
To truly enrich the experience of Sammamish, the summer season serves as a favorable time of visit. From June to August, the temperature averages from 64.4°F (18°C) to 76.5°F (24.7°C), coupled with a relative humidity down to 70%. Furthermore, daylight duration extends beyond 15 hours daily and sunshine up to 10.5 hours, making outdoor activities more enjoyable. Additionally, the scarce rainfall of 0.35" (9mm) per month in July and August contributes to a dry summer, enhancing the conditions for a visit.The worst time to visit Sammamish
On the counter side, the winter months, namely from November to February, might be less appealing to tourists. The mercury drops to an average of between 42.3°F (5.7°C) and 45.1°F (7.3°C). The relative humidity rises to 85% coupled with a shorter period of daylight, only around 9 hours. Additionally, the highest annual rainfall of 1.85" (47mm) in December and a visibility of 5 miles due to the increased cloud cover of 57% can hinder outdoor activities.Spring weather in Sammamish
Spring in Sammamish witnesses a gradual transition in weather conditions. March registers an average high temperature of 50°F (10°C) and an average low of 36.1°F (2.3°C). By May, this high temperature reaches up to 64.4°F (18°C), while the low hovers around 42.6°F (5.9°C). Average rainfall in spring is between 1.3" (33mm) in March and 0.79" (20mm) in May. The city also heaves a sigh of relief with increased daylight hours, from 11.9 hours in March to 15.2 hours in May.Summer weather in Sammamish
Sammamish's summer climate is relatively pleasant with moderate heat. The temperature swings between a pleasant 69.3°F (20.7°C) in June and a warm 76.5°F (24.7°C) in August. Nights remain comfortable with a low ranging from 46.4°F (8°C) to 52.2°F (11.2°C). Summer also sees a drop in precipitation to as low as 0.35" (9mm) in July and August.Autumn weather in Sammamish
Autumn in Sammamish marks the transition from summer to winter. September bears a high temperature of 69.8°F (21°C) that drops to 48.2°F (9°C) by November. Nights during autumn get cooler, with the mercury falling from 48.9°F (9.4°C) in September to 38.3°F (3.5°C) in November. Rainfall begins to rise in this period, from 1.06" (27mm) in September to 1.54" (39mm) in November.Winter weather in Sammamish
Winter in Sammamish, from December to February, is moderately cold. High temperatures in winter months hover between 42.3°F (5.7°C) and 45.1°F (7.3°C), while the average lows stay between 33.6°F (0.9°C) and 34.3°F (1.3°C). Heavy rainfall is prominent in December, with an average rain measurement of 1.85" (47mm). Snowfall is infrequent, with an average of 0.35" (9mm) in December and below 1.38" (35mm) in February. The shortest daylight period is in December with only 8.5 hours, supported by 4.2 hours of sunshine.Weather in January
The start of a new year in Sammamish, Washington brings along colder temperatures, making it one of the more chillier months in this region. The average low temperatures revolve around 34.3°F (1.3°C) and the high around 44.1°F (6.7°C). Weather in January »Weather in February
February witnesses a slight increase in temperature marking a subtle transition towards spring. However, the distinction is noticeable with February experiencing significantly higher snowfall - a total of 1.38" (35mm) in the month, almost double than January, indicating a strong winter still in effect. Weather in February »Weather in March
Weather in March is characterised by a considerable rise in temperatures. As compared to February, the amount of snowfall drastically falls, indicating the retreat of winter and the arrival of spring. Although rainfall continues its steady course with minor variations from February, the amount of snowfall reduces to 0.63" (16mm) this month, a testament to the waning winter season. Weather in March »Weather in April
As the community transitions from winter to spring, April showcases moderate increase in temperatures as compared to March. The city witnesses no snowfall during this month, signalling the complete retreat of winter. Humidity makes a noticeable dip to 80% from the beginning of the year, marking a decrease in moisture levels in the atmosphere. Weather in April »Weather in May
May offers a marked departure from the cooler temperatures of spring to the incoming warmth of summer. As Sammamish transitions into a warmer season, the city experiences a maximum temperature of 64.4°F (18°C). This change in climate is also seen in the declining rainfall, which is at its second lowest in the year. Weather in May »Weather in June
Weather in June defines the commencement of summer in Sammamish, with temperatures reaching an average high of 69.3°F (20.7°C). The city welcomes its longest days in June, with daylight lasting approximately 15.9 hours providing plenty of time for outdoor activities. Weather in June »Weather in July
July is renowned for hosting the highest temperatures in Sammamish, marking the peak of summer with an average peak of 76.1°F (24.5°C). This summertime heat is partly offset by the lowest levels of humidity found throughout the year, standing at 70%. Weather in July »Weather in August
Continuing the summer trend from July, August in Sammamish is characterized by warm weather conditions, with minimal variation in the maximum recorded temperature. The amount of rainfall further dips to just 0.35" (9mm), tying with July for the least amount in any month. Weather in August »Weather in September
September marks a transition period in Sammamish with the city moving from hot summer months towards cooler Fall. Despite the average temperatures starting to decrease, the city still enjoys a maximum of a balmy 69.8°F (21°C). Weather in September »Weather in October
October witnesses a more visible transition towards colder weather in Sammamish. There is a significant drop in maximum temperatures as compared to September, alluding to a chilly autumn. October sees a rise in rainfall compared to the previous month with a total of 1.46" (37mm) indicating the increasing humidity. Weather in October »Weather in November
November in Sammamish is distinctly cooler, confirming the onset of winter. With the average maximum temperature dipping to 48.2°F (9°C), the chilly weather begins to take hold. Interestingly, this month sees the city's highest rainfall at 1.54" (39mm), highest in the year, confirming the wintery conditions. Weather in November »Weather in December
December marks the pinnacle of winter in Sammamish, characterised by the year’s lowest average temperature, falling to 33.6°F (0.9°C). The season brings forth a mild amount of snowfall, with the city receiving 0.35" (9mm) in December, creating a white winter spectacle. Weather in December »Updated: Aug 31, 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, February and December, with an average relative humidity of 85%, are most humid months.
Throughout the year, there are 136.7 rainfall days, and 13.39" (340mm) of precipitation is accumulated.
January through April, November and December are months with snowfall.
In Sammamish, during the entire year, snow falls for 9.3 days and aggregates up to 3.27" (83mm) of snow.
January and December, with an average of 4.2h of sunshine, are months with the least sunshine in Sammamish.
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
February is the month with the most snowfall. Snow falls for 3.2 days and accumulates 1.38" (35mm) of snow.
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.
In Sammamish, snow does not fall in May through October.
With an average of 15h and 54min of daylight, June has the longest days of the year.
The months with the highest UV index are June and July, with an average maximum UV index of 5.
With an average relative humidity of 70%, July is the least humid month.
The months with the least rainfall are July and August Rain falls for 6.7 days and accumulates 0.35" (9mm) of rain.
With average temperatures fluctuating between a high of 76.5°F (24.7°C) and a low of 52.2°F (11.2°C), August stands out as the warmest month.
The month with the most sunshine is August, with an average of 10.7h of sunshine.
December, recording an average high temperature of 42.3°F (5.7°C) and a low temperature of 33.6°F (0.9°C), is Sammamish's coldest month.
The month with the most rainfall is December, when the rain falls for 14.1 days and typically aggregates up to 1.85" (47mm) of precipitation.
December has the shortest days of the year, with an average of 8h and 30min of daylight.
Average temperature
Sammamish, WA
The warmest month (with the highest average high temperature) is August (76.5°F).
The month with the lowest average high temperature is December (42.3°F).
The month with the highest average low temperature is August (52.2°F).
The coldest month (with the lowest average low temperature) is December (33.6°F).
Average pressure
Sammamish, WA
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.06"Hg - Average pressure in March:
30.01"Hg - Average pressure in April:
30.04"Hg - Average pressure in May:
30.02"Hg - Average pressure in June:
30.01"Hg
- Average pressure in July:
30.03"Hg - Average pressure in August:
30"Hg - Average pressure in September:
30.01"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.04"Hg - Average pressure in December:
30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed
Sammamish, WA
- Average wind speed in January:
5mph - Average wind speed in February:
4.6mph - Average wind speed in March:
4.8mph - Average wind speed in April:
4.3mph - Average wind speed in May:
3.8mph - Average wind speed in June:
3.6mph
- Average wind speed in July:
3.5mph - Average wind speed in August:
3.4mph - Average wind speed in September:
3.7mph - Average wind speed in October:
4.1mph - Average wind speed in November:
4.7mph - Average wind speed in December:
4.6mph
The windiest month (with the highest average wind speed) is January (5mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity
Sammamish, WA
The months with the highest relative humidity are January, February and December (85%).
The month with the lowest relative humidity is July (70%).
Average rainfall
Sammamish, WA
- Average rainfall in January:
1.46" - Average rainfall in February:
1.26" - Average rainfall in March:
1.3" - Average rainfall in April:
1.22" - Average rainfall in May:
0.79" - Average rainfall in June:
0.75"
- Average rainfall in July:
0.35" - Average rainfall in August:
0.35" - Average rainfall in September:
1.06" - Average rainfall in October:
1.46" - Average rainfall in November:
1.54" - Average rainfall in December:
1.85"
The wettest month (with the highest rainfall) is December (1.85").
The driest months (with the least rainfall) are July and August (0.35").
Average rainfall days
Sammamish, WA
- Average rainfall days in January:
12.8 days - Average rainfall days in February:
11.2 days - Average rainfall days in March:
14.8 days - Average rainfall days in April:
14 days - Average rainfall days in May:
10.5 days - Average rainfall days in June:
10 days
- Average rainfall days in July:
6.7 days - Average rainfall days in August:
5.2 days - Average rainfall days in September:
10.1 days - Average rainfall days in October:
12.8 days - Average rainfall days in November:
14.5 days - Average rainfall days in December:
14.1 days
The month with the highest number of rainy days is March (14.8 days).
The month with the least rainy days is August (5.2 days).
Average snowfall
Sammamish, WA
The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Sammamish, WA
- Average snowfall days in January:
1.8 days - Average snowfall days in February:
3.2 days - Average snowfall days in March:
2 days - Average snowfall days in April:
0.4 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:
0.1 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0.5 days - Average snowfall days in December:
1.3 days
The month with the highest number of snowfall days is February (3.2 days).
The months with the least snowfall days are May, June, July, August and October (0 days).
Average daylight / Average sunshine
Sammamish, WA
- Average daylight in January:
9h and 0min - Average daylight in February:
10h and 18min - Average daylight in March:
11h and 54min - Average daylight in April:
13h and 42min - Average daylight in May:
15h and 12min - Average daylight in June:
15h and 54min
- Average daylight in July:
15h and 30min - Average daylight in August:
14h and 12min - Average daylight in September:
12h and 30min - Average daylight in October:
10h and 48min - Average daylight in November:
9h and 18min - Average daylight in December:
8h and 30min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in January:
4h and 12min - Average sunshine in February:
4h and 24min - Average sunshine in March:
6h and 6min - Average sunshine in April:
7h and 54min - Average sunshine in May:
9h and 0min - Average sunshine in June:
9h and 18min
- Average sunshine in July:
10h and 30min - Average sunshine in August:
10h and 42min - Average sunshine in September:
9h and 12min - Average sunshine in October:
5h and 30min - Average sunshine in November:
4h and 30min - Average sunshine in December:
4h and 12min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The months with the least sunshine are January and December (Average sunshine: 4h and 12min).
Average sunshine days
Sammamish, WA
- Average sunshine days in January:
15.8 days - Average sunshine days in February:
13.8 days - Average sunshine days in March:
14.3 days - Average sunshine days in April:
13.9 days - Average sunshine days in May:
17.7 days - Average sunshine days in June:
16.3 days
- Average sunshine days in July:
22.3 days - Average sunshine days in August:
24 days - Average sunshine days in September:
17.7 days - Average sunshine days in October:
16.3 days - Average sunshine days in November:
13.5 days - Average sunshine days in December:
15.2 days
The month with the most sunshine days is August (24 days).
The month with the least sunshine days is November (13.5 days).
Average UV index
Sammamish, WA
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover
Sammamish, WA
The month with the most cloud cover is December (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility
Sammamish, WA
The months with the highest visibility are June, July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, May, October, November and December (5mi).
