Sammamish, Washington climate: NOAA's gridded normals for the city, beside the nearest station records
NOAA's gridded 1991-2020 normals put Sammamish's center at January lows of 36°F and July highs of 76°F, a yearly mean of 51.9°F and 48.3 inches of precipitation. No NOAA station keeps a record under the city's name. The nearest station record, Snoqualmie (10 miles E, 440 ft), has January lows of 36°F and July highs of 76°F.
66,474 people (Census Bureau 2024). Distances and directions are from the city's center.
- Jan 47° 36°
- Feb 49° 36°
- Mar 53° 37°
- Apr 58° 41°
- May 65° 47°
- Jun 69° 51°
- Jul 76° 55°
- Aug 76° 55°
- Sep 70° 51°
- Oct 60° 44°
- Nov 51° 39°
- Dec 45° 35°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
The months above are NOAA's gridded normals at Sammamish's center.
What is each month like in Sammamish?
NOAA's grid estimates the normals every 5 km or so from the stations around each point, terrain included. It smooths between stations, so night lows at the heart of a large city can run warmer than the grid shows: at five big-city airports we compared, the grid's highs were within about 1°F of the station and its lows 1-6°F cooler. The nearest record's high and low are beside each month.
| Month | High | Low | Mean | Precip. | Snoqualmie high | Snoqualmie low |
|---|---|---|---|---|---|---|
| January | 47°F | 36°F | 41.2°F | 6.61 | 46°F | 36°F |
| February | 49°F | 36°F | 42.4°F | 4.47 | 50°F | 35°F |
| March | 53°F | 37°F | 45.4°F | 5.16 | 54°F | 37°F |
| April | 58°F | 41°F | 49.6°F | 3.86 | 59°F | 40°F |
| May | 65°F | 47°F | 55.7°F | 2.81 | 64°F | 46°F |
| June | 69°F | 51°F | 60.0°F | 2.19 | 69°F | 51°F |
| July | 76°F | 55°F | 65.1°F | 0.97 | 76°F | 54°F |
| August | 76°F | 55°F | 65.4°F | 1.16 | 77°F | 54°F |
| September | 70°F | 51°F | 60.5°F | 2.20 | 70°F | 49°F |
| October | 60°F | 44°F | 52.0°F | 4.85 | 60°F | 44°F |
| November | 51°F | 39°F | 44.7°F | 7.22 | 51°F | 38°F |
| December | 45°F | 35°F | 40.3°F | 6.76 | 46°F | 36°F |
In metric: a yearly mean of 11.1°C, January lows of 2°C, July highs of 24°C and 1,226 mm of precipitation a year.
Source: NOAA NCEI U.S. Monthly Gridded Climate Normals 1991-2020 (nClimGrid, accession 0245564); NOAA NCEI 1991-2020 station normals. The grid cell holding the city's Census center point.
What do the station records around Sammamish say?
Each row is a NOAA station's own 1991-2020 normals, with the snow and frost dates the grid does not give. A record downhill or nearer the coast than the city can run warmer, one uphill cooler: compare the elevations.
| Record | Where | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| SnoqualmieSnoqualmie Falls | 10 mi E | 440 ft | 51.7°F | 36°F | 76°F | 63.3 | 4 | March 30 |
| RentonRenton Municipal Airport | 11 mi SW | 29 ft | 53.6°F | 37°F | 77°F | 34.7 | – | March 13 |
| Seattle Sand Point Weather Office | 12 mi NW | 60 ft | 53.2°F | 37°F | 77°F | 37.8 | 4 | March 8 |
Source: NOAA NCEI 1991-2020 U.S. Climate Normals; place center and population: Census Bureau 2024. Last frost: the median last spring date of 32°F.
How much snow, how late a frost, what zone and how much sun in Sammamish?
NOAA's grid gives no snow, frost dates or records, so these come from the nearest station record, Snoqualmie (10 miles E, 440 ft). It gets 4 inches of snow in a normal year. The last spring frost (32°F) comes after March 30 in half of years and the first autumn frost before November 7. Its record high is 104°F (1906) and its record low −3°F (1950) (kept since 1899).
The USDA's 2023 Plant Hardiness Zone Map puts Sammamish in zone 8b across its 3 ZIP code areas.
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area (3.8 kWh per square metre a day, NASA POWER 2001-2020); July is the sunniest month (86%) and December the cloudiest (54%).
Snoqualmie's page has its months, frost probabilities, records by month and recent years. NOAA's grid has monthly figures only, so there are no day-by-day month pages for Sammamish; the nearest record's month pages have them.
Source: NOAA NCEI 1991-2020 normals, station USC00457773; records: ACIS; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; sunshine: NASA POWER.
How does the climate vary across Sammamish, ZIP code by ZIP code?
3 ZIP code areas lie wholly or partly in Sammamish. On NOAA's grid 98074 is the warmest (52.0°F a year) and 98075 the coolest (51.9°F), so the city is nearly uniform. Each row also names the nearest station record and its frost dates.
| ZIP code | Zone | Year | Jan low | Jul high | Precip. | Nearest record | Last frost | First frost |
|---|---|---|---|---|---|---|---|---|
| 98029 | 8b | 51.9°F | 36°F | 76°F | 47.4 | Snoqualmie (8 mi) | March 30 | November 7 |
| 98074 | 8b | 52.0°F | 36°F | 76°F | 45.2 | Seattle Sand Point Weather Office (11 mi) | March 8 | November 23 |
| 98075 | 8b | 51.9°F | 36°F | 76°F | 48.3 | Snoqualmie (10 mi) | March 30 | November 7 |
Source: Census Bureau 2020 ZCTA-to-place relationship file and ZCTA centers; NOAA NCEI gridded and station normals, 1991-2020. A ZIP area counts when at least a tenth of its land (and 0.5 km²) is in the city; its figures are the grid cell at its center; frost dates are the nearest record's medians of 32°F.