August weather forecastIssaquah, WA
August
Weather in August
August carries forward the warm temperatures from July with a further increase to 77°F (25°C) on average. The rainfall also shows an infinitesimal rise to 0.28" (7mm). Meanwhile, the evenings stay warmer as August records the highest average low temperature in the year at 51.4°F (10.8°C). The cloud cover marginally increases from 29% in July to 27% in August. Overall, the weather in August in Issaquah is characteristically warm, sunny, and mildly humid.Temperature
The warmest time of the year is August, with temperatures averaging a high of 77°F (25°C) and a low of 51.4°F (10.8°C).Humidity
In August, the average relative humidity is 71%.Rainfall
In Issaquah, in August, during 4.3 rainfall days, 0.28" (7mm) of precipitation is typically accumulated. Throughout the year, there are 127.4 rainfall days, and 12.52" (318mm) of precipitation is accumulated.Snowfall
In Issaquah, snow does not fall in May through October.Daylight
In August, the average length of the day is 14h and 12min.On the first day of August, sunrise is at 5:47 am and sunset at 8:41 pm. On the last day of the month, sunrise is at 6:26 am and sunset at 7:49 pm PDT.
Sunshine
The month with the most sunshine is August, with an average of 10.5h of sunshine.UV index
In Issaquah, Washington, the average daily maximum UV index in August is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: In August, a daily maximum UV index of 4 leads to the following instructions:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Issaquah, WA
- Average high temperature in August: 77°F
The warmest month (with the highest average high temperature) is August (77°F).
The month with the lowest average high temperature is December (42.3°F).
- Average low temperature in August: 51.4°F
The month with the highest average low temperature is August (51.4°F).
The coldest months (with the lowest average low temperature) are February and December (33.4°F).
Average pressure in August
Issaquah, WA
- Average pressure in August: 30"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 in August
Issaquah, WA
- Average wind speed in August: 3.4mph
The windiest month (with the highest average wind speed) is January (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in August
Issaquah, WA
- Average humidity in August: 71%
The months with the highest relative humidity are January and February (85%).
The month with the lowest relative humidity is July (69%).
Average rainfall in August
Issaquah, WA
- Average rainfall in August: 0.28"
The wettest month (with the highest rainfall) is December (2.01").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in August
Issaquah, WA
- Average rainfall days in August: 4.3 days
The month with the highest number of rainy days is March (14.8 days).
The month with the least rainy days is August (4.3 days).
Average snowfall in August
Issaquah, WA
- Average snowfall in August: 0"
The month with the highest snowfall is February (0.94").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in August
Issaquah, WA
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in August /
Average sunshine in August
Issaquah, WA
- Average daylight in August: 14h and 12min
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 August: 10h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 4h and 0min).
Average sunshine days in August
Issaquah, WA
- Average sunshine days in August: 25 days
The month with the most sunshine days is August (25 days).
The month with the least sunshine days is February (12.9 days).
Average UV index in August
Issaquah, WA
- Average UV index in August: 4
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in August
Issaquah, WA
- Average cloud cover in August: 27
The months with the most cloud cover are January and December (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in August
Issaquah, WA
- Average visibility in August: 6mi
The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February and December (4mi).
