Richland weather in September: Richland, Washington: normal highs, lows, rain and records for September
Richland in September has a normal high of 79°F and a normal low of 51°F, a daily mean of 65°F, falling from 84°F on the 1st to 73°F by the 30th. Measurable precipitation falls on 3 days in a normal September, 0.29 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 11°C, 7 mm of precipitation in September.
- NOAA stationRichland
- Station IDUSC00457015
- Location46.31°N 119.26°W
- Elevation373 ft (114 m)
- Population64,372
- Jan 41° 29°
- Feb 48° 30°
- Mar 57° 35°
- Apr 65° 41°
- May 74° 48°
- Jun 80° 54°
- Jul 89° 60°
- Aug 88° 59°
- Sep 79° 51°
- Oct 64° 42°
- Nov 49° 34°
- Dec 40° 28°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Richland in September?
The normal high is 79°F and the normal low 51°F, for a daily mean of 65.2°F. September is 8.4°F cooler than August and 12.2°F warmer than October. September is the 4th warmest month of the year in Richland and the 10th wettest. Across the month the normal high falls 11°F, from 84°F on September 1 to 73°F on September 30. From one year to the next September's mean temperature typically moves about 1.8°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 63°F and 67°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 14%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 84°F | 55°F | 9% | 2% |
| September 8 | 82°F | 54°F | 10% | 3% |
| September 15 | 79°F | 52°F | 11% | 4% |
| September 22 | 77°F | 50°F | 12% | 4% |
| September 30 | 73°F | 47°F | 14% | 5% |
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 | 84°F | 55°F | 9% | 2% | 13 h 20 min |
| September 2 | 84°F | 55°F | 9% | 3% | 13 h 20 min |
| September 3 | 83°F | 55°F | 9% | 3% | 13 h 20 min |
| September 4 | 83°F | 55°F | 9% | 3% | 13 h 10 min |
| September 5 | 83°F | 54°F | 9% | 3% | 13 h 10 min |
| September 6 | 82°F | 54°F | 9% | 3% | 13 h 10 min |
| September 7 | 82°F | 54°F | 9% | 3% | 13 h |
| September 8 | 82°F | 54°F | 10% | 3% | 13 h |
| September 9 | 81°F | 53°F | 10% | 3% | 13 h |
| September 10 | 81°F | 53°F | 10% | 3% | 12 h 50 min |
| September 11 | 81°F | 53°F | 10% | 3% | 12 h 50 min |
| September 12 | 80°F | 53°F | 10% | 3% | 12 h 50 min |
| September 13 | 80°F | 52°F | 10% | 3% | 12 h 40 min |
| September 14 | 80°F | 52°F | 11% | 3% | 12 h 40 min |
| September 15 | 79°F | 52°F | 11% | 4% | 12 h 40 min |
| September 16 | 79°F | 51°F | 11% | 4% | 12 h 30 min |
| September 17 | 79°F | 51°F | 11% | 4% | 12 h 30 min |
| September 18 | 78°F | 51°F | 11% | 4% | 12 h 30 min |
| September 19 | 78°F | 51°F | 12% | 4% | 12 h 20 min |
| September 20 | 77°F | 50°F | 12% | 4% | 12 h 20 min |
| September 21 | 77°F | 50°F | 12% | 4% | 12 h 20 min |
| September 22 | 77°F | 50°F | 12% | 4% | 12 h 10 min |
| September 23 | 76°F | 49°F | 12% | 4% | 12 h 10 min |
| September 24 | 76°F | 49°F | 13% | 4% | 12 h 10 min |
| September 25 | 75°F | 49°F | 13% | 4% | 12 h 10 min |
| September 26 | 75°F | 48°F | 13% | 5% | 12 h |
| September 27 | 74°F | 48°F | 13% | 5% | 12 h |
| September 28 | 74°F | 48°F | 14% | 5% | 12 h |
| September 29 | 73°F | 47°F | 14% | 5% | 11 h 50 min |
| September 30 | 73°F | 47°F | 14% | 5% | 11 h 50 min |
- Normal high
- 79°FSeptember average
- Normal low
- 51°FSeptember average
- Precipitation
- 0.29 inmonth total
- Days with precipitation
- 30.01 inch or more
- Days at 90°F or more
- 3
- Daylight
- 13 h 20 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 27
- Days at 80°F or more
- 14
- Sunshine
- 87%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00457015; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Richland in September?
On a given September day the chance of 0.01 inch or more is 11% on average, highest around September 30 (14%). In all, 0.29 in falls on 3 days of a normal September.
In a normal September in Richland, 3 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00457015.
What are the records for September in Richland?
The warmest September temperature on this station's record (since 1944) is 106°F, on September 3, 1950; the coldest is 31°F, on September 28, 1972. The wettest September brought 1.12 in (1959).
The September mean against the 1991-2020 normal of 65.2°F: 2021 65.8°F (+0.6), 2022 68.4°F (+3.2), 2023 65.6°F (+0.4), 2024 69.2°F (+4.0), 2025 70.1°F (+4.9), 2026 64.0°F (−1.2). 5 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 65.8°F | +0.6°F | 0.39 in |
| 2022 | 68.4°F | +3.2°F | 0.03 in |
| 2023 | 65.6°F | +0.4°F | 0.24 in |
| 2024 | 69.2°F | +4.0°F | 0.05 in |
| 2025 | 70.1°F | +4.9°F | 0.43 in |
| 2026 | 64.0°F | −1.2°F | 0.33 in |
Source: records: ACIS, station USC00457015; recent months: ACIS, station USC00457015. Records and recent months use complete months only.
How does September in Richland 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; Richland's is 79°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.