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Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Weather in January
January is an icy winter month in Grand Coulee, Washington, with temperature in the range of an average low of 21.9°F (-5.6°C) and an average high of 32°F (0°C). January's onset brings an average high-temperature of a cold 32°F (0°C), showing a minute difference from December's 31.6°F (-0.2°C). Weather in January »
Weather in February
The last month of the winter, February, is also an icy month in Grand Coulee, Washington, with an average temperature fluctuating between 24.1°F (-4.4°C) and 35.6°F (2°C). Grand Coulee marks the arrival of February with an average high-temperature of a still icy 35.6°F (2°C), hardly different from January's 32°F (0°C). Weather in February »
Weather in March
The first month of the spring, March, is a chilly month in Grand Coulee, Washington, with an average temperature fluctuating between 32°F (0°C) and 46°F (7.8°C). March signals a shift in the average high-temperature, moving from February's wintry 35.6°F (2°C) to a frosty 46°F (7.8°C). Weather in March »
Weather in April
April is a refreshing spring month in Grand Coulee, Washington, with temperature in the range of an average low of 37.9°F (3.3°C) and an average high of 57°F (13.9°C). As April sets, the average high-temperature shows an increase, moving up from a frosty 46°F (7.8°C) in March to a refreshing 57°F (13.9°C). Weather in April »
Weather in May
May, the last month of the spring in Grand Coulee, is a refreshing month, with an average temperature varying between 67.6°F (19.8°C) and 46°F (7.8°C). Grand Coulee experiences a temperature shift with the start of May, with average high-temperatures moving from a mild 57°F (13.9°C) in April to a comfortable 67.6°F (19.8°C). Weather in May »
Weather in June
The first month of the summer, June, is a warm month in Grand Coulee, Washington, with an average temperature fluctuating between 51.8°F (11°C) and 74.3°F (23.5°C). Entering June, Grand Coulee notices a subtle temperature elevation, with the average high-temperature advancing from May's refreshing 67.6°F (19.8°C) to a warm 74.3°F (23.5°C). Weather in June »
Weather in July
July, the same as June, is another warm summer month in Grand Coulee, Washington, with an average temperature ranging between max 84.9°F (29.4°C) and min 59.7°F (15.4°C). Grand Coulee's temperatures peak on average in July, reaching 84.9°F (29.4°C) at their highest and 59.7°F (15.4°C) at their lowest. Weather in July »
Weather in August
The last month of the summer, August, is also a moderately hot month in Grand Coulee, Washington, with an average temperature fluctuating between 84.2°F (29°C) and 61.3°F (16.3°C). As Grand Coulee transitions into August, the average high-temperature stands at a still moderately hot 84.2°F (29°C), offering little variation from the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is also an agreeable month in Grand Coulee, Washington, with an average temperature varying between 53.2°F (11.8°C) and 72.7°F (22.6°C). The transition into September involves a decrease in the average high-temperature, falling from a moderately hot 84.2°F (29°C) in August to a pleasant 72.7°F (22.6°C). Weather in September »
Weather in October
October, the same as September, in Grand Coulee, Washington, is another mild autumn month, with temperature in the range of an average high of 56.3°F (13.5°C) and an average low of 41.4°F (5.2°C). As September gives way to October, the average high-temperature displays a considerable decrease, falling from an agreeable 72.7°F (22.6°C) to a refreshing 56.3°F (13.5°C). Weather in October »
Weather in November
The last month of the autumn, November, is also a wintry month in Grand Coulee, Washington, with temperature in the range of an average low of 30.7°F (-0.7°C) and an average high of 41.4°F (5.2°C). In November, the average high-temperature decreases considerably from a mild 56.3°F (13.5°C) in October to a cold 41.4°F (5.2°C). Weather in November »
Weather in December
December, the first month of the winter in Grand Coulee, is also a subzero cold month, with an average temperature fluctuating between 31.6°F (-0.2°C) and 21.4°F (-5.9°C). December, with its average high-temperature of 31.6°F (-0.2°C) and an average low-temperature of 21.4°F (-5.9°C), holds the record as the coldest month. Weather in December »
[Resources]Frequently asked questions
What is the most humid month in Grand Coulee?
The most humid month in Grand Coulee is January, with an average relative humidity of 89%.
How much does it rain in Grand Coulee?
In Grand Coulee, during the entire year, the rain falls for 102.1 days and collects up to 9.65" (245mm) of precipitation.
When does it snow in Grand Coulee?
Months with snowfall in Grand Coulee are January through April, September through December.
When does it snow the most in Grand Coulee?
January is the month with the most snowfall in Grand Coulee, Washington. Snow falls for 8.4 days and accumulates 4.41" (112mm) of snow.
How many days does it snow in Grand Coulee?
Throughout the year, there are 33.4 snowfall days, and 14.65" (372mm) of snow is accumulated.
What is the month with the least sunshine in Grand Coulee?
With an average of 4.1h of sunshine, January has the least sunshine of the year.
When is Daylight Saving Time (DST) in Grand Coulee?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Grand Coulee, Washington, 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.
What is the rainiest month in Grand Coulee?
The wettest months are May and December, with an average 1.18" (30mm) of rainfall.
When it does not snow in Grand Coulee?
In Grand Coulee, Washington, snow does not fall in May through August.
When are the longest days in Grand Coulee?
June has the longest days of the year in Grand Coulee, Washington, with an average of 16h and 0min of daylight.
What time of the year is the hottest in Grand Coulee?
The warmest period tends to be July, when average temperatures fluctuate between a high of 84.9°F (29.4°C) and a low of 59.7°F (15.4°C).
What is the driest month in Grand Coulee?
July and August are months with the least rain in Grand Coulee, Washington, when the rain falls for 4.2 days and typically aggregates up to 0.2" (5mm) of rain.
When is the highest UV index in Grand Coulee?
July is the month with the highest UV index in Grand Coulee, with an average maximum UV index of 7.
What is the least humid month in Grand Coulee?
August is the least humid month in Grand Coulee, with an average relative humidity of 36%.
What month has the most sunshine in Grand Coulee?
The month with the most sunshine in Grand Coulee is August, with an average of 12.1h of sunshine.
What is the month with the lowest UV index in Grand Coulee?
With an average maximum UV index of 1, November is the month with the lowest UV index in Grand Coulee.
What time of the year is the coldest in Grand Coulee?
Grand Coulee's December weather, with an average high temperature of 31.6°F (-0.2°C) and an average low temperature of 21.4°F (-5.9°C), tends to be the coldest of the year.
What is the month with the shortest days in Grand Coulee?
With an average of 8h and 30min of daylight, December has the shortest days of the year.
Average temperature
Grand Coulee, WA
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (31.6°F).
The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).
Average pressure
Grand Coulee, WA
- Average pressure in January:
30.18"Hg - Average pressure in February:
30.1"Hg - Average pressure in March:
30.01"Hg - Average pressure in April:
29.98"Hg - Average pressure in May:
29.94"Hg - Average pressure in June:
29.92"Hg
- Average pressure in July:
29.93"Hg - Average pressure in August:
29.91"Hg - Average pressure in September:
29.96"Hg - Average pressure in October:
30.03"Hg - Average pressure in November:
30.08"Hg - Average pressure in December:
30.15"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed
Grand Coulee, WA
- Average wind speed in January:
4.9mph - Average wind speed in February:
5.3mph - Average wind speed in March:
6.3mph - Average wind speed in April:
7mph - Average wind speed in May:
6.3mph - Average wind speed in June:
6.3mph
- Average wind speed in July:
6mph - Average wind speed in August:
5.7mph - Average wind speed in September:
5.8mph - Average wind speed in October:
5.9mph - Average wind speed in November:
5.8mph - Average wind speed in December:
5mph
The windiest month (with the highest average wind speed) is April (7mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).
Average humidity
Grand Coulee, WA
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (36%).
Average rainfall
Grand Coulee, WA
- Average rainfall in January:
1.14" - Average rainfall in February:
0.75" - Average rainfall in March:
1.06" - Average rainfall in April:
0.79" - Average rainfall in May:
1.18" - Average rainfall in June:
0.75"
The wettest months (with the highest rainfall) are May and December (1.18").
The driest months (with the least rainfall) are July and August (0.2").
Average rainfall days
Grand Coulee, WA
- Average rainfall days in January:
9.7 days - Average rainfall days in February:
7.8 days - Average rainfall days in March:
12.1 days - Average rainfall days in April:
11.1 days - Average rainfall days in May:
10.8 days - Average rainfall days in June:
8.4 days
- Average rainfall days in July:
4.2 days - Average rainfall days in August:
3.2 days - Average rainfall days in September:
5.5 days - Average rainfall days in October:
10.3 days - Average rainfall days in November:
10.5 days - Average rainfall days in December:
8.5 days
The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (3.2 days).
Average snowfall
Grand Coulee, WA
The month with the highest snowfall is January (4.41").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days
Grand Coulee, WA
- Average snowfall days in January:
8.4 days - Average snowfall days in February:
6.9 days - Average snowfall days in March:
3.2 days - Average snowfall days in April:
0.8 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:
0.2 days - Average snowfall days in November:
3.3 days - Average snowfall days in December:
10.5 days
The month with the highest number of snowfall days is December (10.5 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight / Average sunshine
Grand Coulee, WA
- Average daylight in January:
8h and 5min - Average daylight in February:
10h and 2min - Average daylight in March:
11h and 5min - Average daylight in April:
13h and 4min - Average daylight in May:
15h and 1min - Average daylight in June:
16h and 0min
- Average daylight in July:
15h and 4min - Average daylight in August:
14h and 1min - Average daylight in September:
12h and 4min - Average daylight in October:
10h and 5min - Average daylight in November:
9h and 2min - Average daylight in December:
8h and 3min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in January:
4h and 1min - Average sunshine in February:
4h and 5min - Average sunshine in March:
7h and 2min - Average sunshine in April:
10h and 1min - Average sunshine in May:
10h and 5min - Average sunshine in June:
11h and 2min
- Average sunshine in July:
11h and 5min - Average sunshine in August:
12h and 1min - Average sunshine in September:
10h and 4min - Average sunshine in October:
6h and 4min - Average sunshine in November:
5h and 3min - Average sunshine in December:
4h and 2min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days
Grand Coulee, WA
- Average sunshine days in January:
16 days - Average sunshine days in February:
14.8 days - Average sunshine days in March:
14.7 days - Average sunshine days in April:
15.8 days - Average sunshine days in May:
18 days - Average sunshine days in June:
19.9 days
- Average sunshine days in July:
25.5 days - Average sunshine days in August:
25.8 days - Average sunshine days in September:
23.3 days - Average sunshine days in October:
19.2 days - Average sunshine days in November:
15.4 days - Average sunshine days in December:
16 days
The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is March (14.7 days).
Average UV index
Grand Coulee, WA
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is November (UV index 1).
Average cloud cover
Grand Coulee, WA
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility
Grand Coulee, WA
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (4mi).
Grand Coulee, Washington, USA
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