Understanding local atmospheric cycles matters whether you're moving to the Pacific Northwest or planning an extended stay. Redmond, Washington experiences a classic warm-summer Mediterranean climate (classified as Csb), defined by dry, comfortable summers and wet, overcast winters. Annual precipitation hovers around 42 to 44 inches, but how that moisture distributes across twelve months shapes daily life, outdoor recreation, and local ecology.
Temperature ranges across the year stay relatively moderate compared to continental interiors, kept stable by the moderating influence of the Puget Sound and the Pacific Ocean. Winter lows rarely plunge into deep historic freezes, and summer heatwaves, while increasingly intense, remain brief interludes in an otherwise temperate cycle. Looking at a full year of weather patterns reveals distinct seasonal shifts that define life in this corner of King County.
Spring: Transition and Increasing Variability
Spring in Redmond acts as a prolonged atmospheric handshake between cold winter conditions and dry summer stability. Spanning March through May, this season brings gradual warming alongside persistent variability.
Average high temperatures climb from about 54°F in March to a comfortable 66°F by May. Overnight lows remain chilly, hovering between 36°F and 48°F during these months. Rain remains a frequent companion, though total accumulation begins to taper down from winter peaks. March still logs over fifteen days of measurable precipitation, while May sees averages drop closer to 2.5 inches.
Gardeners and growers track the last spring frost closely, which typically occurs between mid-to-late March. Plant hardiness lands firmly in Zone 9a, making spring the prime window for planting cool-season crops and perennial landscaping before drier conditions set in.
Summer: Dry Spells and Maximum Sunshine
Summer represents the crown jewel of the Redmond climate calendar. Lasting roughly from late June through mid-September, this period brings reliable sunshine, low humidity, and minimal rainfall.
July and August stand out as the warmest months of the year, sharing average afternoon highs of 77°F. Overnight lows settle into a crisp, refreshing 56°F to 58°F, making air conditioning unnecessary for many older homes. Precipitation drops dramatically; July is famously dry, averaging less than an inch of rain across just a handful of damp days.
- Clear Skies: August boasts the highest percentage of clear days, with sunshine dominating nearly 70% of daylight hours.
- Microclimates: Proximity to local parks, tree canopies, and the Sammamish River Valley can create localized temperature pockets during warm afternoons.
- Dryness Risks: Extended dry stretches often elevate seasonal wildfire smoke risks arriving from regional forest fires elsewhere in the Pacific Northwest.
Autumn: The Great Return of Precipitation
Autumn arrives abruptly in Redmond, usually breaking the pleasant summer weather pattern by late September or early October.
October introduces sharper temperature drops, with average highs falling back to 60°F and nights cooling to 45°F. Rainfall escalates quickly. While summer months feel parched, November takes the crown as the wettest month of the entire year, dumping an average of 6.6 to 8.7 inches of rain across the city.
The transition involves heavy cloud cover, shortening daylight hours, and saturated soils. Fallen leaves combined with persistent autumn downpours mean local storm drains require regular clearing to prevent localized street pooling.
Winter: Overcast Skies and Damp Cold
Winter in Redmond spans December through February, characterized by overcast skies, high relative humidity, and damp chill.
December is the coldest month, featuring average daytime highs of 46°F and overnight lows dipping right around freezing at 36°F. Total snowfall is minor—averaging roughly 10 inches annually—and heavy accumulations remain rare. Most winter precipitation falls as cold rain rather than snow.
According to data compiled by the National Weather Service, regional winter weather can occasionally be disrupted by arctic air outflows rushing through mountain passes, bringing brief periods of icy conditions and crisp, clear skies. Otherwise, persistent gray cloud cover defines the season, keeping sunshine hours to a minimum.
Common Weather Misconceptions in Redmond
Many newcomers hold inaccurate assumptions about how the local climate functions. Clearing up these misconceptions helps residents prepare effectively for year-round conditions.
- "It rains every single day." While winter features many overcast and drizzly days, summer months are exceptionally dry. Annual rainfall totals in Redmond are comparable to many major East Coast cities, but the Pacific Northwest distributes that rain heavily across the winter months.
- "You don't need sun protection outside of summer." UV rays bounce off clouds and water vapor. Even on overcast spring days, skin protection remains essential during long outdoor excursions.
- "Snow shuts the city down completely." Because true snow events are infrequent, major infrastructure manages standard winter rain efficiently. However, rare freezing rain or sudden snowfalls require caution on hilly local terrain.
Frequently Asked Questions
What is the hottest month in Redmond, Washington?
August is consistently the warmest month of the year, bringing average afternoon highs of 77°F and plenty of clear skies.
How much rain does Redmond get annually?
The city averages between 42 and 44 inches of precipitation per year, with the vast majority falling between October and March.
Does it snow frequently in Redmond?
Snowfall is light and sporadic, averaging around 10 inches per year. Many winters see only minor dustings that melt away within a day or two.
When is the best time of year to visit Redmond for outdoor activities?
Mid-July through late August offers the most reliable weather window, featuring warm temperatures, minimal rainfall, and maximum daily sunshine.
