September
September · August · June
88climate match
United States · 1991–2020
Best time to visit
Carbonate (historical).
September leads for comfortable weather in Carbonate (historical): typically 24°C by day, 9.7°C at night, with 43 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high24°C
Typical low9.7°C
Rain in September43 mm
August
August · July · September
76climate match
September
September · May · October
84climate match
The weakest month is January, scoring 5 against September’s 88 — days reach only 3.1°C, 21° below the 24°C the score treats as ideal, and nights drop to -8.2°C.
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
53.1° / -8.2°
Feb
53.5° / -8.1°
Mar
138.8° / -3.3°
Apr
3413.8° / 1.2°
May
5219° / 6.6°
Jun
7425.1° / 12°
Jul
7229.9° / 15.6°
Aug
7729.2° / 14.6°
Sep
8824° / 9.7°
Oct
4615.5° / 2.9°
Nov
178.8° / -2.7°
Dec
53.7° / -7.2°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 3.1°C | -8.2°C | 18 mm | 4.7 | 9 h 11 | 5 | Strong coverage |
| February | 3.5°C | -8.1°C | 25 mm | 4.9 | 10 h 22 | 5 | Strong coverage |
| March | 8.8°C | -3.3°C | 36 mm | 6.6 | 11 h 46 | 13 | Strong coverage |
| April | 13.8°C | 1.2°C | 59 mm | 7.8 | 13 h 24 | 34 | Strong coverage |
| May | 19°C | 6.6°C | 105 mm | 10.5 | 14 h 46 | 52 | Strong coverage |
| June | 25.1°C | 12°C | 107 mm | 10.3 | 15 h 31 | 74 | Strong coverage |
| July | 29.9°C | 15.6°C | 59 mm | 7.8 | 15 h 13 | 72 | Strong coverage |
| August | 29.2°C | 14.6°C | 50 mm | 6 | 14 h 02 | 77 | Strong coverage |
| September | 24°C | 9.7°C | 43 mm | 4.8 | 12 h 28 | 88 | Strong coverage |
| October | 15.5°C | 2.9°C | 48 mm | 5.7 | 10 h 54 | 46 | Strong coverage |
| November | 8.8°C | -2.7°C | 23 mm | 4 | 9 h 32 | 17 | Strong coverage |
| December | 3.7°C | -7.2°C | 25 mm | 4.8 | 8 h 51 | 5 | Strong coverage |
What has changed
Carbonate (historical) runs -0.0°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
+0.9
Feb
-2.0
Mar
+1.4
Apr
-1.0
May
-1.2
Jun
+0.6
Jul
-0.1
Aug
-0.8
Sep
+1.6
Oct
-1.2
Nov
+0.8
Dec
+0.6
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 26.1°C19 Jan 1921 | -35.6°C4 Jan 1950 | 38 mm16 Jan 1897 | 57 mm1897 · driest 0 mm in 1919 | 124 |
| February | 23.9°C22 Feb 1982 | -36.1°C14 Feb 2021 | 42 mm2 Feb 1924 | 91 mm1924 · driest 0 mm in 1989 | 128 |
| March | 27.8°C22 Mar 1910 | -32.8°C4 Mar 2019 | 97 mm27 Mar 1950 | 134 mm1950 · driest 2 mm in 1904 | 130 |
| April | 32.8°C22 Apr 1980 | -22.2°C4 Apr 1920 | 90 mm19 Apr 1903 | 151 mm1986 · driest 7 mm in 1913 | 130 |
| May | 35.6°C14 May 2001 | -11.7°C1 May 1909 | 165 mm11 May 1922 | 358 mm1982 · driest 4 mm in 1934 | 128 |
| June | 40.6°C18 Jun 1893 | -3.9°C3 Jun 1951 | 164 mm15 Jun 1976 | 356 mm1976 · driest 8 mm in 1919 | 128 |
| July | 43.3°C6 Jul 1936 | 0.6°C15 Jul 1906 | 88 mm29 Jul 1932 | 199 mm1923 · driest 4 mm in 1947 | 131 |
| August | 40.0°C12 Aug 1938 | 0.0°C26 Aug 1906 | 93 mm3 Aug 1922 | 130 mm1972 · driest 1 mm in 1898 | 130 |
| September | 40.6°C7 Sep 1978 | -9.4°C25 Sep 1926 | 76 mm28 Sep 1923 | 157 mm1923 · driest 0 mm in 1897 | 129 |
| October | 35.0°C15 Oct 1908 | -21.7°C26 Oct 2020 | 70 mm5 Oct 2013 | 191 mm2013 · driest 0 mm in 1907 | 127 |
| November | 29.4°C18 Nov 1908 | -30.6°C16 Nov 1959 | 72 mm1 Nov 2000 | 180 mm1944 · driest 0 mm in 1917 | 124 |
| December | 22.8°C2 Dec 1920 | -34.4°C30 Dec 1968 | 51 mm16 Dec 1921 | 73 mm1951 · driest 0 mm in 1905 | 126 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 26 | <1 | 5 |
| February | 0 | 0 | 24 | <1 | 5 |
| March | <1 | 0 | 21 | <1 | 4 |
| April | 2 | <1 | 12 | 2 | 2 |
| May | 5 | 1 | 2 | 3 | <1 |
| June | 15 | 6 | 0 | 3 | 0 |
| July | 25 | 15 | 0 | 2 | 0 |
| August | 25 | 15 | 0 | 2 | 0 |
| September | 13 | 5 | <1 | 1 | <1 |
| October | 3 | <1 | 9 | 1 | 1 |
| November | <1 | 0 | 19 | <1 | 3 |
| December | 0 | 0 | 26 | <1 | 5 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | <1% | 13% | <1% | 8% | -2.5–6.8°C |
| February | <1% | 15% | 1% | 9% | -1.7–7.8°C |
| March | 5% | 19% | 3% | 14% | 2.9–11.4°C |
| April | 21% | 23% | 6% | 22% | 10.4–17.3°C |
| May | 39% | 29% | 9% | 35% | 16.2–22.4°C |
| June | 60% | 32% | 10% | 36% | 21.8–28.3°C |
| July | 77% | 22% | 6% | 18% | 26.5–32.6°C |
| August | 81% | 18% | 5% | 13% | 26.4–31.4°C |
| September | 68% | 16% | 4% | 12% | 20.5–26.6°C |
| October | 34% | 16% | 4% | 10% | 12.7–19.5°C |
| November | 7% | 14% | 2% | 8% | 4.8–12.5°C |
| December | <1% | 14% | 1% | 8% | -0.6–7.1°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 5763355
- NOAA station
- USC00397882 · SPEARFISH
- Station distance
- 10.8 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 25 usable years
- Daylight
- Calculated from latitude 44.40°, 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.