Sequim weather in September: Sequim, Washington: normal highs, lows, rain and records for September
Sequim in September has a normal high of 66°F and a normal low of 46°F, a daily mean of 56°F, falling from 69°F on the 1st to 62°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 0.87 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 19°C and low of 8°C, 22 mm of precipitation in September.
- NOAA stationSequim (2 mi E)
- Station IDUSC00457544
- Location48.09°N 123.06°W
- Elevation50 ft (15 m)
- Population8,199
- Jan 46° 32°
- Feb 48° 32°
- Mar 51° 35°
- Apr 56° 38°
- May 62° 44°
- Jun 65° 49°
- Jul 70° 52°
- Aug 70° 51°
- Sep 66° 46°
- Oct 58° 40°
- Nov 50° 35°
- Dec 46° 32°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Sequim in September?
The normal high is 66°F and the normal low 46°F, for a daily mean of 56.0°F. September is 4.7°F cooler than August and 7.3°F warmer than October. September is the 4th warmest month of the year in Sequim and the 10th wettest. Across the month the normal high falls 7°F, from 69°F on September 1 to 62°F on September 30. From one year to the next September's mean temperature typically moves about 1.7°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 54°F and 58°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 34%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 69°F | 49°F | 22% | 7% |
| September 8 | 68°F | 48°F | 25% | 8% |
| September 15 | 66°F | 46°F | 28% | 9% |
| September 22 | 65°F | 45°F | 31% | 10% |
| September 30 | 62°F | 43°F | 34% | 12% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 69°F | 49°F | 22% | 7% | 13 h 30 min |
| September 2 | 69°F | 49°F | 23% | 7% | 13 h 20 min |
| September 3 | 69°F | 49°F | 23% | 7% | 13 h 20 min |
| September 4 | 68°F | 49°F | 23% | 8% | 13 h 20 min |
| September 5 | 68°F | 48°F | 24% | 8% | 13 h 10 min |
| September 6 | 68°F | 48°F | 24% | 8% | 13 h 10 min |
| September 7 | 68°F | 48°F | 25% | 8% | 13 h 10 min |
| September 8 | 68°F | 48°F | 25% | 8% | 13 h |
| September 9 | 68°F | 48°F | 26% | 8% | 13 h |
| September 10 | 67°F | 47°F | 26% | 8% | 13 h |
| September 11 | 67°F | 47°F | 26% | 8% | 12 h 50 min |
| September 12 | 67°F | 47°F | 27% | 8% | 12 h 50 min |
| September 13 | 67°F | 47°F | 27% | 9% | 12 h 50 min |
| September 14 | 67°F | 47°F | 28% | 9% | 12 h 40 min |
| September 15 | 66°F | 46°F | 28% | 9% | 12 h 40 min |
| September 16 | 66°F | 46°F | 29% | 9% | 12 h 40 min |
| September 17 | 66°F | 46°F | 29% | 9% | 12 h 30 min |
| September 18 | 66°F | 46°F | 30% | 9% | 12 h 30 min |
| September 19 | 65°F | 46°F | 30% | 10% | 12 h 30 min |
| September 20 | 65°F | 45°F | 31% | 10% | 12 h 20 min |
| September 21 | 65°F | 45°F | 31% | 10% | 12 h 20 min |
| September 22 | 65°F | 45°F | 31% | 10% | 12 h 20 min |
| September 23 | 64°F | 45°F | 32% | 10% | 12 h 10 min |
| September 24 | 64°F | 45°F | 32% | 10% | 12 h 10 min |
| September 25 | 64°F | 44°F | 32% | 11% | 12 h 10 min |
| September 26 | 63°F | 44°F | 33% | 11% | 12 h |
| September 27 | 63°F | 44°F | 33% | 11% | 12 h |
| September 28 | 63°F | 44°F | 34% | 11% | 11 h 50 min |
| September 29 | 63°F | 43°F | 34% | 11% | 11 h 50 min |
| September 30 | 62°F | 43°F | 34% | 12% | 11 h 50 min |
- Normal high
- 66°FSeptember average
- Normal low
- 46°FSeptember average
- Precipitation
- 0.87 inmonth total
- Days with precipitation
- 90.01 inch or more
- Daylight
- 13 h 30 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 7
- Sunshine
- 76%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00457544; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Sequim in September?
On a given September day the chance of 0.01 inch or more is 28% on average, highest around September 30 (34%). In all, 0.87 in falls on 9 days of a normal September.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00457544.
What are the records for September in Sequim?
The warmest September temperature on this station's record (since 1980) is 87°F, on September 5, 2017; the coldest is 31°F, on September 29, 1983. The wettest September brought 3.12 in (1983).
The September mean against the 1991-2020 normal of 56.0°F: 2021 57.9°F (+1.9), 2022 60.0°F (+4.0), 2024 59.5°F (+3.5), 2025 60.4°F (+4.4), 2026 58.6°F (+2.6). 5 of 5 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 57.9°F | +1.9°F | 2.06 in |
| 2022 | 60.0°F | +4.0°F | 0.00 in |
| 2024 | 59.5°F | +3.5°F | 0.73 in |
| 2025 | 60.4°F | +4.4°F | 0.72 in |
| 2026 | 58.6°F | +2.6°F | 1.25 in |
Source: records: ACIS, station USC00457544; recent months: ACIS, station USC00457544. Records and recent months use complete months only.
How does September in Sequim compare across Washington?
Across the 96 places PlainClimate covers in Washington, September normal highs run from 66°F in Coupeville to 81°F in Pasco; Sequim's is 66°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.