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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, the same as December, is an icy winter month in Mattawa, Washington, with temperature in the range of an average low of 25.9°F (-3.4°C) and an average high of 35.4°F (1.9°C). The weather during January records an average high-temperature of a still wintry 35.4°F (1.9°C), closely mirroring the preceding month. Weather in January »
Weather in February
The last month of the winter, February, is another cold month in Mattawa, Washington, with an average temperature ranging between min 29.1°F (-1.6°C) and max 41.4°F (5.2°C). Observing a minor shift, the average high-temperature during February adjusts from January's wintry 35.4°F (1.9°C) to a still cold 41.4°F (5.2°C). Weather in February »
Weather in March
March, the first month of the spring in Mattawa, is a cool month, with an average temperature fluctuating between 35.8°F (2.1°C) and 51.4°F (10.8°C). As Mattawa transitions into March, a rise in the average high-temperature is observed, moving from a cold 41.4°F (5.2°C) in February to a cool 51.4°F (10.8°C). Weather in March »
Weather in April
April in Mattawa, Washington, is an enjoyable spring month, with an average temperature fluctuating between 41.5°F (5.3°C) and 61.3°F (16.3°C). The beginning of April signals a rise in the average high-temperature, moving from a cool 51.4°F (10.8°C) in March to a refreshing 61.3°F (16.3°C). Weather in April »
Weather in May
May, the last month of the spring in Mattawa, is an agreeable month, with temperature in the range of an average low of 49.1°F (9.5°C) and an average high of 71.2°F (21.8°C). With the onset of May, Mattawa's average high-temperature experiences a rise, moving from April's refreshing 61.3°F (16.3°C) to a pleasant 71.2°F (21.8°C). Weather in May »
Weather in June
The first month of the summer, June, is a moderately hot month in Mattawa, Washington, with temperature in the range of an average high of 78.6°F (25.9°C) and an average low of 54.1°F (12.3°C). June showcases a minor temperature ascent, adjusting from May's pleasant 71.2°F (21.8°C) to a moderately hot 78.6°F (25.9°C). Weather in June »
Weather in July
July is a tropical summer month in Mattawa, Washington, with an average temperature fluctuating between 60.4°F (15.8°C) and 88.3°F (31.3°C). In Mattawa, the months of July and August register the highest average temperatures, peaking at 88.3°F (31.3°C). Weather in July »
Weather in August
The last month of the summer, August, is another hot month in Mattawa, Washington, with an average temperature fluctuating between 88.3°F (31.3°C) and 61.5°F (16.4°C). Mattawa's highest average temperatures are recorded in July and August, reaching a high of 88.3°F (31.3°C). Weather in August »
Weather in September
The first month of the autumn, September, is still a warm month in Mattawa, Washington, with temperature in the range of an average low of 54.7°F (12.6°C) and an average high of 76.1°F (24.5°C). A change in temperatures is noted as August gives way to September, with average highs reducing from a tropical 88.3°F (31.3°C) to a warm 76.1°F (24.5°C). Weather in September »
Weather in October
October, like September, is another mild autumn month in Mattawa, Washington, with an average temperature fluctuating between 43.7°F (6.5°C) and 60.1°F (15.6°C). In October, the average high-temperature decreases considerably from a warm 76.1°F (24.5°C) in September to a mild 60.1°F (15.6°C). Weather in October »
Weather in November
November, the last month of the autumn in Mattawa, is also a frosty month, with temperature in the range of an average low of 32.9°F (0.5°C) and an average high of 45.5°F (7.5°C). The beginning of November signals a clear reduction in the average high-temperature, falling from a mild 60.1°F (15.6°C) in October to a frosty 45.5°F (7.5°C). Weather in November »
Weather in December
December, the first month of the winter in Mattawa, is still a cold month, with an average temperature ranging between max 34.5°F (1.4°C) and min 24.3°F (-4.3°C). December is the month that records the lowest temperatures, with averages ranging from a high of 34.5°F (1.4°C) to a low of 24.3°F (-4.3°C). Weather in December »
Updated: Jun 29, 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
What is the most humid month?
With an average relative humidity of 83%, January is the most humid month.
What is the wettest month?
The months with the most rainfall are January and December, with an average 0.87" (22mm) of precipitation.
How much does it rain?
In Mattawa, during the entire year, the rain falls for 86.4 days and collects up to 6.38" (162mm) of precipitation.
When does it snow?
Months with snowfall are January through April, September, November and December.
How much does it snow?
In Mattawa, during the entire year, snow falls for 22.3 days and aggregates up to 10" (254mm) of snow.
What is the month with the least sunshine?
With an average of 4.9h of sunshine, January has the least sunshine of the year.
What are the months with the lowest UV index?
The months with the lowest UV index in Mattawa are January, February, November and December, with an average maximum UV index of 2.
When is Daylight Saving Time (DST)?
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.
When it does not snow?
May through August and October are months without snowfall.
When are the longest days?
The month with the longest days is June, with an average of 15h and 48min of daylight.
What part of the year is the hottest?
Mattawa experiences its warmest period in July and August, averaging a high-temperature of 88.3°F (31.3°C).
What is the least humid month?
With an average relative humidity of 37%, July is the least humid month in Mattawa.
What are the months with the most sunshine?
July and August, with an average of 12h of sunshine, are months with the most sunshine.
When is the highest UV index?
The month with the highest UV index is July, with an average maximum UV index of 7.
What is the driest month?
The month with the least rainfall is August, when the rain falls for 3.5 days and typically collects 0.2" (5mm) of precipitation.
What is the coldest time of year?
December, with its high-temperature average of 34.5°F (1.4°C) and a low-temperature average of 24.3°F (-4.3°C), is the coldest month.
When does it snow the most?
December is the month with the most snowfall. Snow falls for 6.5 days and accumulates 3.43" (87mm) of snow.
What is the month with the shortest days?
With an average of 8h and 36min of daylight, December has the shortest days of the year.
Average temperature
Mattawa, WA
The warmest months (with the highest average high temperature) are July and August (88.3°F).
The month with the lowest average high temperature is December (34.5°F).
The month with the highest average low temperature is August (61.5°F).
The coldest month (with the lowest average low temperature) is December (24.3°F).
Average pressure
Mattawa, WA
- Average pressure in January:
30.17"Hg - Average pressure in February:
30.09"Hg - Average pressure in March:
30.01"Hg - Average pressure in April:
29.99"Hg - Average pressure in May:
29.95"Hg - Average pressure in June:
29.93"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:
30.14"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed
Mattawa, WA
- Average wind speed in January:
4.9mph - Average wind speed in February:
5.8mph - Average wind speed in March:
6.8mph - Average wind speed in April:
7.6mph - Average wind speed in May:
7.1mph - Average wind speed in June:
7.2mph
- Average wind speed in July:
6.8mph - Average wind speed in August:
6.4mph - Average wind speed in September:
6.3mph - Average wind speed in October:
5.8mph - Average wind speed in November:
5.8mph - Average wind speed in December:
4.7mph
The windiest month (with the highest average wind speed) is April (7.6mph).
The calmest month (with the lowest average wind speed) is December (4.7mph).
Average humidity
Mattawa, WA
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is July (37%).
Average rainfall
Mattawa, WA
- Average rainfall in January:
0.87" - Average rainfall in February:
0.59" - Average rainfall in March:
0.67" - Average rainfall in April:
0.39" - Average rainfall in May:
0.71" - Average rainfall in June:
0.43"
- Average rainfall in July:
0.24" - Average rainfall in August:
0.2" - Average rainfall in September:
0.31" - Average rainfall in October:
0.59" - Average rainfall in November:
0.51" - Average rainfall in December:
0.87"
The wettest months (with the highest rainfall) are January and December (0.87").
The driest month (with the least rainfall) is August (0.2").
Average rainfall days
Mattawa, WA
- Average rainfall days in January:
8.5 days - Average rainfall days in February:
7.6 days - Average rainfall days in March:
10.6 days - Average rainfall days in April:
8.8 days - Average rainfall days in May:
8.2 days - Average rainfall days in June:
5.5 days
- Average rainfall days in July:
3.8 days - Average rainfall days in August:
3.5 days - Average rainfall days in September:
4.1 days - Average rainfall days in October:
8.6 days - Average rainfall days in November:
9.3 days - Average rainfall days in December:
7.9 days
The month with the highest number of rainy days is March (10.6 days).
The month with the least rainy days is August (3.5 days).
Average snowfall
Mattawa, WA
The month with the highest snowfall is December (3.43").
The months with the least snowfall are May, June, July, August and October (0").
Average snowfall days
Mattawa, WA
- Average snowfall days in January:
6.3 days - Average snowfall days in February:
5 days - Average snowfall days in March:
2.1 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:
0.1 days - Average snowfall days in November:
1.8 days - Average snowfall days in December:
6.5 days
The month with the highest number of snowfall days is December (6.5 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight / Average sunshine
Mattawa, WA
- Average daylight in January:
9h and 1min - Average daylight in February:
10h and 2min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 4min - Average daylight in May:
15h and 1min - Average daylight in June:
15h and 5min
- Average daylight in July:
15h and 2min - Average daylight in August:
14h and 1min - Average daylight in September:
12h and 3min - Average daylight in October:
10h and 5min - Average daylight in November:
9h and 2min - Average daylight in December:
8h and 4min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in January:
4h and 5min - Average sunshine in February:
5h and 3min - Average sunshine in March:
7h and 5min - Average sunshine in April:
10h and 2min - Average sunshine in May:
11h and 0min - Average sunshine in June:
11h and 3min
- Average sunshine in July:
12h and 0min - Average sunshine in August:
12h and 0min - Average sunshine in September:
10h and 5min - Average sunshine in October:
6h and 5min - Average sunshine in November:
6h and 1min - Average sunshine in December:
5h and 1min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 54min).
Average sunshine days
Mattawa, WA
- Average sunshine days in January:
18 days - Average sunshine days in February:
16 days - Average sunshine days in March:
17.1 days - Average sunshine days in April:
19 days - Average sunshine days in May:
20.9 days - Average sunshine days in June:
23 days
- Average sunshine days in July:
25.8 days - Average sunshine days in August:
25.8 days - Average sunshine days in September:
24.3 days - Average sunshine days in October:
20.9 days - Average sunshine days in November:
17.9 days - Average sunshine days in December:
18.1 days
The months with the most sunshine days are July and August (25.8 days).
The month with the least sunshine days is February (16 days).
Average UV index
Mattawa, WA
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover
Mattawa, WA
The month with the most cloud cover is January (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 10).
Average visibility
Mattawa, WA
The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).
Mattawa, Washington, USA
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