Weather by Month in Washington

Washington experiences distinct seasons, with warm July days averaging 31°C / 88°F and cool January nights dropping to -2°C / 28°F. Rainfall averages 96 mm / 3.8 inches per month, with July typically the wettest. June offers the longest days with around 15 hours of daylight.

Monthly Climate Comparison

The biggest temperature swing occurs between October and November, with a change of 6.4°C / 43.5°F.

Month Low Temperature High Temperature Category
January -2.4°C 6°C COLD
February -1.7°C 8°C COLD
March 2.1°C 12.7°C COOL
April 7.6°C 18.9°C MILD
May 13°C 23.5°C WARM
June 18.3°C 28.6°C WARM
July 21.1°C 30.9°C HOT
August 20.4°C 29.8°C WARM
September 16.8°C 25.9°C WARM
October 10.4°C 19.7°C MILD
November 4.4°C 13.4°C COOL
December 0.1°C 8.3°C COOL

Rain & Sunshine Patterns

Driest Months

#1 February
Best for: outdoor activities & sightseeing
#2 November
Best for: outdoor activities & sightseeing
#3 January
Best for: outdoor activities & sightseeing

Wettest Months

#1 July
Expect: possible showers, pack waterproofs
#2 September
Expect: possible showers, pack waterproofs
#3 August
Expect: possible showers, pack waterproofs

UV & Sun Protection Calendar

High UV Alert:
March, April, May, June, July, August, September require serious sun protection.
Jan
4
MODERATE
Feb
5
MODERATE
Mar
6
HIGH
Apr
7
HIGH
May
8
HIGH
Jun
8
VERY-HIGH
Jul
8
VERY-HIGH
Aug
8
HIGH
Sep
7
HIGH
Oct
5
MODERATE
Nov
4
MODERATE
Dec
3
LOW-MOD
Extreme (11+)
Avoid sun during midday, use SPF 50+
Very High (8-10)
Essential sun protection required
High (6-7)
Use SPF 30+, wear hat & sunglasses
Moderate (3-5)
Sun protection recommended
Low-Moderate (1-2)
Minimal protection needed
Low (0)
No protection required

Daylight Hours

Daylight varies from 9.5 hours in December (winter) to 14.8 hours in June (summer), which is a difference of 5.3 hours.

Shortest Days

December
9.5h
Average Sunrise:07:18
Average Sunset:16:48
Plan daytime activities for midday when light is best. Early sunsets mean evening plans should account for darkness.

Longest Days

June
14.8h
Average Sunrise:04:43
Average Sunset:19:33
Extended daylight perfect for evening activities and late dining. You can fit more sightseeing into each day.

Wind & Humidity Overview

Wind Conditions

Average wind speed
Windiest months:
March (12 km/h) January (12 km/h) April (12 km/h)
Packing tip: Conditions are generally calm, but a light layer is always handy.

Humidity Levels

Average humidity
69%
Most humid:
September (72%)
Least humid:
March (65%)
Packing tip: Light, moisture-wicking fabrics work well for active days.

Seasonal Overview

Northern Hemisphere seasons shape the weather patterns throughout the year. Here's what to expect in each season:

Winter

January, February, December
Avg High 7°C
Avg Low -1°C
Avg Rain 83 mm
Cool weather; bring layers and a jacket

Spring

March, April, May
Avg High 18°C
Avg Low 8°C
Avg Rain 96 mm
Warming trend with frequent showers; pack waterproofs

Summer

June, July, August
Avg High 30°C
Avg Low 20°C
Avg Rain 109 mm
Warm and pleasant; perfect for travel

Autumn

September, October, November
Avg High 20°C
Avg Low 11°C
Avg Rain 95 mm
Wet season begins; bring rain gear

Monthly Details

Click any month for detailed weather information and packing advice.

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Frequently Asked Questions

What is the best month to visit Washington?

The best months to visit Washington depend on your preferences. For warm weather, July is typically the warmest month. For dry conditions, February, November, January tend to have the least rainfall. Consider your priorities, and whether you prefer warmer temperatures, drier weather, or longer daylight hours.

When is Washington warmest?

July is typically the warmest month in Washington, with average high temperatures reaching around 31°C (88°F). This is peak summer weather, ideal for outdoor activities and sightseeing.

When is Washington coldest?

January is usually the coldest month, with average low temperatures dropping to around -2°C (28°F). Pack warm layers if visiting during this time, especially for evening activities.

When does Washington get the most rain?

July typically sees the most rainfall in Washington, averaging around 120mm (4.7 inches). It's wise to pack waterproof layers and have some indoor backup plans if you're visiting during this month.

What is the driest month in Washington?

February is typically the driest month, with average rainfall of just 76mm (3.0 inches). This makes it an excellent time for outdoor exploration and activities with minimal risk of rain disruption.

How much does the temperature vary in Washington throughout the year?

Temperatures in Washington range from average lows of 9°C (49°F) to highs of 19°C (66°F). This variation means you'll want to pack differently depending on when you visit, as layers are key for adapting to the seasonal changes.

Do I need sun protection when visiting Washington?

Yes, sun protection is important in Washington. UV levels can reach 8 during peak months, which is considered very high. Pack sunscreen (SPF 30+), sunglasses, and a hat, especially if you'll be outdoors for extended periods.

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