September
September · August · June
79climate match
United States · 1991–2020
Best time to visit
Blackhawk Island.
September leads for comfortable weather in Blackhawk Island: typically 23.3°C by day, 10.7°C at night, with 85 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high23.3°C
Typical low10.7°C
Rain in September85 mm
July
July · August · June
68climate match
May
May · September · October
75climate match
The weakest month is January, scoring 5 against September’s 79 — days reach only -2.4°C, 26° 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
5-2.4° / -11.8°
Feb
5-0.2° / -10.1°
Mar
56.4° / -4°
Apr
3013.9° / 2.4°
May
6120.6° / 8.7°
Jun
7326.1° / 14.3°
Jul
7028.1° / 16.6°
Aug
7627° / 15.4°
Sep
7923.3° / 10.7°
Oct
4516° / 4.3°
Nov
97.6° / -1.9°
Dec
50.6° / -7.8°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | -2.4°C | -11.8°C | 38 mm | 6.6 | 9 h 20 | 5 | Strong coverage |
| February | -0.2°C | -10.1°C | 36 mm | 5.9 | 10 h 28 | 5 | Strong coverage |
| March | 6.4°C | -4°C | 50 mm | 6.7 | 11 h 47 | 5 | Strong coverage |
| April | 13.9°C | 2.4°C | 90 mm | 9.3 | 13 h 20 | 30 | Strong coverage |
| May | 20.6°C | 8.7°C | 105 mm | 10.1 | 14 h 37 | 61 | Strong coverage |
| June | 26.1°C | 14.3°C | 126 mm | 9.2 | 15 h 20 | 73 | Strong coverage |
| July | 28.1°C | 16.6°C | 102 mm | 7.3 | 15 h 03 | 70 | Strong coverage |
| August | 27°C | 15.4°C | 98 mm | 7.7 | 13 h 56 | 76 | Strong coverage |
| September | 23.3°C | 10.7°C | 85 mm | 7.2 | 12 h 26 | 79 | Strong coverage |
| October | 16°C | 4.3°C | 72 mm | 7.4 | 10 h 58 | 45 | Strong coverage |
| November | 7.6°C | -1.9°C | 56 mm | 6.6 | 9 h 40 | 9 | Strong coverage |
| December | 0.6°C | -7.8°C | 43 mm | 6.7 | 9 h 02 | 5 | Strong coverage |
What has changed
Blackhawk Island 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
+1.1
Feb
0.0
Mar
+0.8
Apr
-1.2
May
-0.4
Jun
-0.1
Jul
-0.5
Aug
-0.3
Sep
+1.0
Oct
0.0
Nov
0.0
Dec
+2.1
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 14.4°C5 Jan 1997 | -36.1°C30 Jan 1951 | 43 mm2 Jan 1942 | 93 mm2005 · driest 3 mm in 2025 | 84 |
| February | 22.2°C23 Feb 2017 | -39.4°C3 Feb 1996 | 42 mm9 Feb 2001 | 84 mm2023 · driest 1 mm in 1958 | 84 |
| March | 28.9°C22 Mar 2012 | -29.4°C1 Mar 1962 | 61 mm25 Mar 2009 | 144 mm2009 · driest 7 mm in 1958 | 84 |
| April | 32.2°C23 Apr 1980 | -20.0°C6 Apr 1979 | 69 mm3 Apr 1982 | 198 mm2026 · driest 21 mm in 1946 | 84 |
| May | 35.6°C28 May 2018 | -3.9°C9 May 1966 | 91 mm22 May 2004 | 286 mm2004 · driest 16 mm in 2026 | 84 |
| June | 38.3°C21 Jun 1988 | 0.6°C4 Jun 1945 | 101 mm10 Jun 2016 | 268 mm1968 · driest 11 mm in 2012 | 85 |
| July | 39.4°C6 Jul 2012 | 3.9°C6 Jul 1965 | 112 mm23 Jul 2010 | 226 mm2010 · driest 6 mm in 1946 | 85 |
| August | 38.9°C2 Aug 1988 | 2.8°C28 Aug 1986 | 88 mm19 Aug 2007 | 270 mm2007 · driest 9 mm in 1970 | 84 |
| September | 36.7°C9 Sep 1955 | -2.2°C22 Sep 1974 | 114 mm8 Sep 1941 | 242 mm1961 · driest 10 mm in 2017 | 85 |
| October | 31.1°C14 Oct 1975 | -11.7°C31 Oct 1988 | 78 mm2 Oct 2019 | 179 mm1951 · driest 3 mm in 1952 | 85 |
| November | 25.6°C9 Nov 1999 | -25.6°C30 Nov 1947 | 68 mm1 Nov 1984 | 143 mm1985 · driest 6 mm in 2007 | 85 |
| December | 19.4°C6 Dec 2001 | -33.9°C25 Dec 1983 | 56 mm27 Dec 1942 | 113 mm2007 · driest 5 mm in 1989 | 84 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 30 | 1 | 7 |
| February | 0 | 0 | 27 | 1 | 6 |
| March | <1 | 0 | 24 | 2 | 3 |
| April | 2 | <1 | 10 | 3 | <1 |
| May | 8 | 2 | <1 | 4 | 0 |
| June | 19 | 7 | 0 | 4 | 0 |
| July | 26 | 10 | 0 | 3 | 0 |
| August | 23 | 6 | 0 | 3 | 0 |
| September | 13 | 3 | <1 | 3 | 0 |
| October | 3 | <1 | 7 | 2 | <1 |
| November | 0 | 0 | 20 | 2 | 2 |
| December | 0 | 0 | 28 | 1 | 6 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 19% | 3% | 16% | -5.7–0.8°C |
| February | <1% | 18% | 3% | 15% | -4.0–3.9°C |
| March | 3% | 23% | 5% | 23% | 2.8–9.8°C |
| April | 16% | 30% | 9% | 37% | 11.6–17.2°C |
| May | 43% | 30% | 9% | 35% | 18.6–24.1°C |
| June | 66% | 30% | 12% | 36% | 24.4–28.2°C |
| July | 75% | 24% | 10% | 24% | 26.7–30.4°C |
| August | 74% | 25% | 10% | 24% | 25.3–29.4°C |
| September | 58% | 25% | 9% | 26% | 21.2–25.5°C |
| October | 26% | 22% | 7% | 24% | 13.8–19.3°C |
| November | 3% | 23% | 6% | 21% | 3.7–10.7°C |
| December | 0% | 21% | 3% | 19% | -3.6–3.5°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 5246140
- NOAA station
- USC00472869 · FT ATKINSON WWTP
- Station distance
- 2.8 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 29 usable years
- Daylight
- Calculated from latitude 42.90°, 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.