Kennewick weather in September: Kennewick, Washington: normal highs, lows, rain and records for September
Kennewick in September has a normal high of 81°F and a normal low of 53°F, a daily mean of 67°F, falling from 86°F on the 1st to 74°F by the 30th. Measurable precipitation falls on 3 days in a normal September, 0.26 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 27°C and low of 12°C, 7 mm of precipitation in September.
- NOAA stationKennewick
- Station IDUSC00454154
- Location46.21°N 119.10°W
- Elevation390 ft (119 m)
- From the center4 miles
- Population86,728
- Jan 42° 29°
- Feb 48° 31°
- Mar 58° 36°
- Apr 66° 42°
- May 75° 50°
- Jun 82° 56°
- Jul 91° 62°
- Aug 90° 61°
- Sep 81° 53°
- Oct 66° 43°
- Nov 51° 35°
- Dec 42° 30°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Kennewick in September?
The normal high is 81°F and the normal low 53°F, for a daily mean of 66.8°F. September is 9.0°F cooler than August and 12.3°F warmer than October. September is the 4th warmest month of the year in Kennewick and the 10th wettest. Across the month the normal high falls 12°F, from 86°F on September 1 to 74°F on September 30. From one year to the next September's mean temperature typically moves about 1.9°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 65°F and 69°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 12%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 86°F | 57°F | 7% | 3% |
| September 8 | 84°F | 55°F | 8% | 3% |
| September 15 | 81°F | 53°F | 9% | 3% |
| September 22 | 78°F | 51°F | 10% | 4% |
| September 30 | 74°F | 49°F | 12% | 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 | 86°F | 57°F | 7% | 3% | 13 h 20 min |
| September 2 | 85°F | 57°F | 7% | 3% | 13 h 20 min |
| September 3 | 85°F | 57°F | 8% | 3% | 13 h 20 min |
| September 4 | 85°F | 57°F | 8% | 3% | 13 h 10 min |
| September 5 | 85°F | 56°F | 8% | 3% | 13 h 10 min |
| September 6 | 84°F | 56°F | 8% | 3% | 13 h 10 min |
| September 7 | 84°F | 56°F | 8% | 3% | 13 h |
| September 8 | 84°F | 55°F | 8% | 3% | 13 h |
| September 9 | 83°F | 55°F | 8% | 3% | 13 h |
| September 10 | 83°F | 55°F | 8% | 3% | 12 h 50 min |
| September 11 | 82°F | 55°F | 8% | 3% | 12 h 50 min |
| September 12 | 82°F | 54°F | 8% | 3% | 12 h 50 min |
| September 13 | 82°F | 54°F | 9% | 3% | 12 h 40 min |
| September 14 | 81°F | 54°F | 9% | 3% | 12 h 40 min |
| September 15 | 81°F | 53°F | 9% | 3% | 12 h 40 min |
| September 16 | 81°F | 53°F | 9% | 4% | 12 h 30 min |
| September 17 | 80°F | 53°F | 9% | 4% | 12 h 30 min |
| September 18 | 80°F | 53°F | 10% | 4% | 12 h 30 min |
| September 19 | 79°F | 52°F | 10% | 4% | 12 h 20 min |
| September 20 | 79°F | 52°F | 10% | 4% | 12 h 20 min |
| September 21 | 79°F | 52°F | 10% | 4% | 12 h 20 min |
| September 22 | 78°F | 51°F | 10% | 4% | 12 h 10 min |
| September 23 | 78°F | 51°F | 11% | 4% | 12 h 10 min |
| September 24 | 77°F | 51°F | 11% | 4% | 12 h 10 min |
| September 25 | 77°F | 50°F | 11% | 4% | 12 h 10 min |
| September 26 | 76°F | 50°F | 11% | 4% | 12 h |
| September 27 | 76°F | 50°F | 11% | 4% | 12 h |
| September 28 | 75°F | 49°F | 12% | 5% | 12 h |
| September 29 | 75°F | 49°F | 12% | 5% | 11 h 50 min |
| September 30 | 74°F | 49°F | 12% | 5% | 11 h 50 min |
- Normal high
- 81°FSeptember average
- Normal low
- 53°FSeptember average
- Precipitation
- 0.26 inmonth total
- Days with precipitation
- 30.01 inch or more
- Days at 90°F or more
- 4
- Daylight
- 13 h 20 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 28
- Days at 80°F or more
- 16
- Sunshine
- 87%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00454154; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Kennewick in September?
On a given September day the chance of 0.01 inch or more is 9% on average, highest around September 30 (12%). In all, 0.26 in falls on 3 days of a normal September.
In a normal September in Kennewick, 4 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00454154.
What are the records for September in Kennewick?
The warmest September temperature on this station's record (since 1894) is 100°F, on September 4, 1934; the coldest is 21°F, on September 24, 1926. The wettest September brought 1.79 in (1927).
The September mean against the 1991-2020 normal of 66.8°F: 2021 67.2°F (+0.4), 2022 70.0°F (+3.2), 2023 67.5°F (+0.8), 2024 71.5°F (+4.7), 2025 72.7°F (+5.9), 2026 65.0°F (−1.8). 5 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 67.2°F | +0.4°F | 0.41 in |
| 2022 | 70.0°F | +3.2°F | 0.12 in |
| 2023 | 67.5°F | +0.8°F | 0.15 in |
| 2024 | 71.5°F | +4.7°F | 0.11 in |
| 2025 | 72.7°F | +5.9°F | 0.19 in |
| 2026 | 65.0°F | −1.8°F | 0.25 in |
Source: records: ACIS, station USC00454154; recent months: ACIS, station USC00454154. Records and recent months use complete months only.
How does September in Kennewick 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; Kennewick's is 81°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.