Climate and monthly weather forecastRainier, OR
Climate and monthly weather forecast
Weather in January
January is a chilly winter month in Rainier, Oregon, with an average temperature fluctuating between 44.2°F (6.8°C) and 33.4°F (0.8°C). With the advent of January, Rainier's high-temperatures adjust to a frosty 44.2°F (6.8°C), closely aligning with the preceding month. Weather in January »Weather in February
The last month of the winter, February, is another chilly month in Rainier, Oregon, with an average temperature fluctuating between 33.3°F (0.7°C) and 45.5°F (7.5°C). Rainier experiences a transition to a still chilly 45.5°F (7.5°C) in average high-temperatures with the arrival of February, not greatly differing from January's 44.2°F (6.8°C). Weather in February »Weather in March
March, the first month of the spring in Rainier, is a cool month, with an average temperature fluctuating between 34.7°F (1.5°C) and 50°F (10°C). March's weather records an average high-temperature of a cool 50°F (10°C), showing little deviation from February. Weather in March »Weather in April
April is a refreshing spring month in Rainier, Oregon, with an average temperature varying between 36.7°F (2.6°C) and 55.9°F (13.3°C). The shift from March to April is marked by a slight increase in the average high-temperature, moving from a cool 50°F (10°C) to a mild 55.9°F (13.3°C). Weather in April »Weather in May
The last month of the spring, May, is a comfortable month in Rainier, Oregon, with temperature in the range of an average low of 40.8°F (4.9°C) and an average high of 64.8°F (18.2°C). May's arrival sees a mild rise in the average high-temperature, transitioning from April's refreshing 55.9°F (13.3°C) to an enjoyable 64.8°F (18.2°C). Weather in May »Weather in June
June, the first month of the summer in Rainier, is an agreeable month, with an average temperature varying between 69.4°F (20.8°C) and 44.6°F (7°C). Entering June, the average high-temperature is recorded at a pleasant 69.4°F (20.8°C), exhibiting a minimal shift from May's 64.8°F (18.2°C). Weather in June »Weather in July
July in Rainier, Oregon, is a warm summer month, with an average temperature fluctuating between 76.8°F (24.9°C) and 48.9°F (9.4°C). The transition from June to July brings a subtle temperature rise, with average high-temperatures increasing from an agreeable 69.4°F (20.8°C) to a moderately hot 76.8°F (24.9°C). Weather in July »Weather in August
The last month of the summer, August, is another warm month in Rainier, Oregon, with an average temperature varying between 49.8°F (9.9°C) and 77.9°F (25.5°C). August is the warmest month, exhibiting average temperatures of 77.9°F (25.5°C) at the peak and 49.8°F (9.9°C) at the base. Weather in August »Weather in September
September, the first month of the autumn in Rainier, is also an agreeable month, with an average temperature varying between 70.7°F (21.5°C) and 47.3°F (8.5°C). The onset of September brings a small shift in high-temperatures, falling from a warm 77.9°F (25.5°C) in August to a pleasant 70.7°F (21.5°C). Weather in September »Weather in October
October, the same as September, in Rainier, Oregon, is another mild autumn month, with temperature in the range of an average low of 42.3°F (5.7°C) and an average high of 59°F (15°C). In October, the average high-temperature decreases from a pleasant 70.7°F (21.5°C) in September to a mild 59°F (15°C). Weather in October »Weather in November
November, the last month of the autumn in Rainier, is also a frosty month, with an average temperature fluctuating between 48.4°F (9.1°C) and 37.6°F (3.1°C). In Rainier, the average high-temperature in November decreases from a moderate 59°F (15°C) in October to a frosty 48.4°F (9.1°C). Weather in November »Weather in December
December, the first month of the winter in Rainier, is also a wintry month, with an average temperature fluctuating between 42.3°F (5.7°C) and 32.7°F (0.4°C). December tends to be the coldest month, with temperatures averaging a daily high of 42.3°F (5.7°C) and a low of 32.7°F (0.4°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Rainier, OR
The warmest month (with the highest average high temperature) is August (77.9°F).
The month with the lowest average high temperature is December (42.3°F).
The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (32.7°F).
Average pressure
Rainier, OR
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.07"Hg - Average pressure in March:
30.03"Hg - Average pressure in April:
30.06"Hg - Average pressure in May:
30.04"Hg - Average pressure in June:
30.04"Hg
- Average pressure in July:
30.05"Hg - Average pressure in August:
30.01"Hg - Average pressure in September:
30.01"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.05"Hg - Average pressure in December:
30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed
Rainier, OR
- Average wind speed in January:
4.8mph - Average wind speed in February:
4.5mph - Average wind speed in March:
4.7mph - Average wind speed in April:
4.4mph - Average wind speed in May:
4.2mph - Average wind speed in June:
4.1mph
- Average wind speed in July:
4.3mph - Average wind speed in August:
4mph - Average wind speed in September:
3.9mph - Average wind speed in October:
4.1mph - Average wind speed in November:
4.7mph - Average wind speed in December:
4.7mph
The windiest month (with the highest average wind speed) is January (4.8mph).
The calmest month (with the lowest average wind speed) is September (3.9mph).
Average humidity
Rainier, OR
The months with the highest relative humidity are January, February, November and December (88%).
The month with the lowest relative humidity is July (72%).
Average rainfall
Rainier, OR
- Average rainfall in January:
3.9" - Average rainfall in February:
2.8" - Average rainfall in March:
2.83" - Average rainfall in April:
2.28" - Average rainfall in May:
1.61" - Average rainfall in June:
1.26"
- Average rainfall in July:
0.43" - Average rainfall in August:
0.39" - Average rainfall in September:
1.26" - Average rainfall in October:
2.83" - Average rainfall in November:
2.64" - Average rainfall in December:
3.58"
The wettest month (with the highest rainfall) is January (3.9").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days
Rainier, OR
- Average rainfall days in January:
18.7 days - Average rainfall days in February:
16.7 days - Average rainfall days in March:
20.3 days - Average rainfall days in April:
18.8 days - Average rainfall days in May:
13.9 days - Average rainfall days in June:
12 days
- Average rainfall days in July:
6.1 days - Average rainfall days in August:
6.3 days - Average rainfall days in September:
10.8 days - Average rainfall days in October:
15.9 days - Average rainfall days in November:
17.5 days - Average rainfall days in December:
18.5 days
The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is July (6.1 days).
Average snowfall
Rainier, OR
The month with the highest snowfall is January (1.26").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days
Rainier, OR
- Average snowfall days in January:
1.7 days - Average snowfall days in February:
2.2 days - Average snowfall days in March:
1.4 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:
0.5 days - Average snowfall days in December:
0.9 days
The month with the highest number of snowfall days is February (2.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Rainier, OR
- Average daylight in January:
9h and 6min - Average daylight in February:
10h and 24min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 36min - Average daylight in May:
15h and 0min - Average daylight in June:
15h and 42min
- Average daylight in July:
15h and 18min - Average daylight in August:
14h and 6min - Average daylight in September:
12h and 30min - Average daylight in October:
10h and 54min - Average daylight in November:
9h and 30min - Average daylight in December:
8h and 42min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in January:
3h and 30min - Average sunshine in February:
3h and 30min - Average sunshine in March:
4h and 48min - Average sunshine in April:
6h and 18min - Average sunshine in May:
7h and 54min - Average sunshine in June:
8h and 30min
- Average sunshine in July:
10h and 6min - Average sunshine in August:
10h and 24min - Average sunshine in September:
8h and 24min - Average sunshine in October:
4h and 54min - Average sunshine in November:
3h and 42min - Average sunshine in December:
3h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The months with the least sunshine are January, February and December (Average sunshine: 3h and 30min).
Average sunshine days
Rainier, OR
- Average sunshine days in January:
10.6 days - Average sunshine days in February:
9.1 days - Average sunshine days in March:
8.9 days - Average sunshine days in April:
9.3 days - Average sunshine days in May:
15.3 days - Average sunshine days in June:
15.4 days
- Average sunshine days in July:
22 days - Average sunshine days in August:
21.3 days - Average sunshine days in September:
17 days - Average sunshine days in October:
13.7 days - Average sunshine days in November:
10.5 days - Average sunshine days in December:
10.2 days
The month with the most sunshine days is July (22 days).
The month with the least sunshine days is March (8.9 days).
Average UV index
Rainier, OR
The months with the highest UV index are June and July (UV index 5).
The month with the lowest UV index is November (UV index 1).
Average cloud cover
Rainier, OR
The months with the most cloud cover are February and March (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility
Rainier, OR
The month with the highest visibility is August (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, September, October, November and December (4mi).





