September
September · June · August
72climate match
United States · 1991–2020
Best time to visit
Chesterfield.
September leads for comfortable weather in Chesterfield: typically 23.4°C by day, 8.8°C at night, with 110 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high23.4°C
Typical low8.8°C
Rain in September110 mm
July
July · August · June
58climate match
May
May · September · June
70climate match
The weakest month is January, scoring 5 against September’s 72 — days reach only -0.4°C, 24° below the 24°C the score treats as ideal.
Month by month
The whole year,
without the guesswork.
The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.
Jan
5-0.4° / -11.7°
Feb
51.7° / -11.3°
Mar
56.6° / -6.5°
Apr
2614.1° / -0.7°
May
5720.8° / 5.3°
Jun
7125.4° / 10.6°
Jul
6728.2° / 13.7°
Aug
6927.5° / 12.8°
Sep
7223.4° / 8.8°
Oct
3215.9° / 2.4°
Nov
58.6° / -2.8°
Dec
52.6° / -7.6°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | -0.4°C | -11.7°C | 81 mm | 9.2 | 9 h 21 | 5 | Strong coverage |
| February | 1.7°C | -11.3°C | 70 mm | 7.7 | 10 h 28 | 5 | Strong coverage |
| March | 6.6°C | -6.5°C | 82 mm | 8.6 | 11 h 47 | 5 | Strong coverage |
| April | 14.1°C | -0.7°C | 88 mm | 9.5 | 13 h 19 | 26 | Strong coverage |
| May | 20.8°C | 5.3°C | 96 mm | 10.5 | 14 h 37 | 57 | Strong coverage |
| June | 25.4°C | 10.6°C | 105 mm | 10.2 | 15 h 19 | 71 | Strong coverage |
| July | 28.2°C | 13.7°C | 107 mm | 9.8 | 15 h 03 | 67 | Strong coverage |
| August | 27.5°C | 12.8°C | 110 mm | 8.7 | 13 h 56 | 69 | Strong coverage |
| September | 23.4°C | 8.8°C | 110 mm | 7.5 | 12 h 26 | 72 | Strong coverage |
| October | 15.9°C | 2.4°C | 124 mm | 9.3 | 10 h 58 | 32 | Strong coverage |
| November | 8.6°C | -2.8°C | 88 mm | 8.7 | 9 h 40 | 5 | Strong coverage |
| December | 2.6°C | -7.6°C | 98 mm | 9.6 | 9 h 02 | 5 | Strong coverage |
What has changed
Chesterfield runs -0.2°C
on the 1961–1990 baseline.
Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.
Jan
-0.2
Feb
-0.2
Mar
-0.3
Apr
-0.8
May
-0.7
Jun
-0.8
Jul
-0.1
Aug
0.0
Sep
+0.8
Oct
-0.5
Nov
-0.7
Dec
+0.9
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 18.9°C14 Jan 1932 | -35.6°C5 Jan 1904 | 53 mm25 Jan 1979 | 235 mm1979 · driest 18 mm in 1981 | 133 |
| February | 21.7°C22 Feb 2018 | -37.2°C20 Feb 1936 | 65 mm25 Feb 2016 | 241 mm2008 · driest 2 mm in 1987 | 134 |
| March | 30.6°C29 Mar 1998 | -29.4°C4 Mar 1950 | 72 mm7 Mar 2011 | 198 mm2024 · driest 1 mm in 1915 | 132 |
| April | 33.9°C28 Apr 1990 | -17.2°C1 Apr 1923 | 58 mm17 Apr 1996 | 173 mm1996 · driest 9 mm in 1941 | 133 |
| May | 36.7°C22 May 1911 | -7.2°C11 May 1900 | 97 mm30 May 1984 | 277 mm1984 · driest 22 mm in 1911 | 132 |
| June | 36.7°C20 Jun 1953 | -2.8°C8 Jun 1932 | 93 mm26 Jun 2014 | 209 mm1998 · driest 10 mm in 1913 | 132 |
| July | 40.0°C3 Jul 1911 | 1.1°C1 Jul 1936 | 103 mm18 Jul 2021 | 430 mm2021 · driest 27 mm in 1929 | 133 |
| August | 38.9°C5 Aug 1955 | -2.8°C26 Aug 1940 | 90 mm7 Aug 1901 | 247 mm2011 · driest 8 mm in 1996 | 132 |
| September | 38.3°C2 Sep 1953 | -7.2°C29 Sep 1914 | 111 mm17 Sep 1999 | 264 mm1938 · driest 5 mm in 1948 | 131 |
| October | 32.2°C7 Oct 1963 | -12.2°C28 Oct 1936 | 220 mm9 Oct 2005 | 420 mm2005 · driest 6 mm in 1924 | 132 |
| November | 26.7°C2 Nov 1982 | -26.1°C26 Nov 1938 | 80 mm26 Nov 1950 | 195 mm1927 · driest 13 mm in 2012 | 130 |
| December | 21.1°C8 Dec 1998 | -33.9°C30 Dec 1933 | 64 mm1 Dec 2020 | 180 mm1996 · driest 13 mm in 1943 | 131 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 30 | 3 | 8 |
| February | 0 | 0 | 27 | 3 | 7 |
| March | <1 | 0 | 28 | 3 | 5 |
| April | 2 | <1 | 19 | 3 | 1 |
| May | 9 | 2 | 5 | 3 | 0 |
| June | 18 | 5 | <1 | 3 | 0 |
| July | 27 | 11 | 0 | 4 | 0 |
| August | 24 | 8 | 0 | 3 | 0 |
| September | 12 | 2 | 1 | 3 | 0 |
| October | 1 | 0 | 13 | 3 | <1 |
| November | 0 | 0 | 23 | 3 | 2 |
| December | 0 | 0 | 29 | 4 | 6 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 31% | 9% | 32% | -2.9–2.6°C |
| February | 0% | 30% | 9% | 30% | -1.4–4.2°C |
| March | 2% | 31% | 10% | 35% | 3.7–9.9°C |
| April | 15% | 34% | 10% | 42% | 11.7–16.7°C |
| May | 44% | 35% | 11% | 41% | 18.8–23.9°C |
| June | 62% | 34% | 11% | 38% | 23.6–27.3°C |
| July | 66% | 33% | 12% | 34% | 26.6–29.6°C |
| August | 68% | 31% | 11% | 31% | 25.3–28.8°C |
| September | 55% | 29% | 11% | 29% | 21.0–24.9°C |
| October | 22% | 28% | 10% | 29% | 14.4–18.7°C |
| November | 2% | 32% | 10% | 36% | 6.5–11.3°C |
| December | <1% | 31% | 11% | 33% | -0.7–4.7°C |
A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.
The evidence behind this page
Nearby, measured,
and named.
- Place identity
- GeoNames 5084524
- NOAA station
- USC00274399 · KEENE
- Station distance
- 13.2 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 28 usable years
- Daylight
- Calculated from latitude 42.89°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Important limit
- Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.