September
September · August · June
79climate match
United States · 1991–2020
Best time to visit
Alden.
September leads for comfortable weather in Alden: typically 23.8°C by day, 10.3°C at night, with 90 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high23.8°C
Typical low10.3°C
Rain in September90 mm
July
July · August · June
66climate match
September
September · October · May
73climate match
The weakest month is January, scoring 5 against September’s 79 — days reach only -3.4°C, 27° 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
5-3.4° / -13.3°
Feb
5-0.7° / -11°
Mar
56.5° / -4.1°
Apr
3014.7° / 1.9°
May
5721.2° / 8.6°
Jun
6726.7° / 14.6°
Jul
6728.3° / 16.7°
Aug
7427.1° / 15.3°
Sep
7923.8° / 10.3°
Oct
4616.5° / 3.4°
Nov
77.2° / -3.6°
Dec
5-0.3° / -9.6°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | -3.4°C | -13.3°C | 25 mm | 4.9 | 9 h 23 | 5 | Strong coverage |
| February | -0.7°C | -11°C | 30 mm | 4.7 | 10 h 29 | 5 | Strong coverage |
| March | 6.5°C | -4.1°C | 54 mm | 6.2 | 11 h 48 | 5 | Strong coverage |
| April | 14.7°C | 1.9°C | 103 mm | 9.4 | 13 h 19 | 30 | Strong coverage |
| May | 21.2°C | 8.6°C | 143 mm | 11.3 | 14 h 35 | 57 | Strong coverage |
| June | 26.7°C | 14.6°C | 156 mm | 10.1 | 15 h 17 | 67 | Strong coverage |
| July | 28.3°C | 16.7°C | 117 mm | 7.7 | 15 h 00 | 67 | Strong coverage |
| August | 27.1°C | 15.3°C | 114 mm | 8 | 13 h 54 | 74 | Strong coverage |
| September | 23.8°C | 10.3°C | 90 mm | 7.3 | 12 h 26 | 79 | Strong coverage |
| October | 16.5°C | 3.4°C | 67 mm | 6.8 | 10 h 59 | 46 | Strong coverage |
| November | 7.2°C | -3.6°C | 49 mm | 5.4 | 9 h 42 | 7 | Strong coverage |
| December | -0.3°C | -9.6°C | 37 mm | 5.6 | 9 h 04 | 5 | Strong coverage |
What has changed
Alden 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
+0.4
Feb
-0.6
Mar
+0.6
Apr
-1.2
May
-1.3
Jun
0.0
Jul
-1.0
Aug
-0.5
Sep
+1.2
Oct
0.0
Nov
+0.4
Dec
+2.1
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 20.0°C27 Jan 2002 | -36.7°C12 Jan 1912 | 50 mm4 Jan 1971 | 79 mm1982 · driest 1 mm in 1976 | 133 |
| February | 24.4°C27 Feb 2024 | -35.6°C13 Feb 1905 | 58 mm22 Feb 1922 | 102 mm1915 · driest 0 mm in 1960 | 130 |
| March | 31.1°C22 Mar 2026 | -35.0°C1 Mar 1962 | 47 mm6 Mar 1946 | 127 mm1991 · driest 0 mm in 1910 | 131 |
| April | 36.1°C22 Apr 1980 | -16.1°C7 Apr 1911 | 97 mm25 Apr 2008 | 210 mm2013 · driest 12 mm in 1946 | 132 |
| May | 41.7°C31 May 1934 | -7.8°C4 May 1907 | 87 mm27 May 2013 | 313 mm2024 · driest 16 mm in 1934 | 132 |
| June | 41.7°C27 Jun 1934 | 1.1°C12 Jun 1903 | 143 mm2 Jun 1942 | 392 mm1998 · driest 21 mm in 1955 | 133 |
| July | 43.9°C14 Jul 1936 | 2.2°C9 Jul 1895 | 159 mm31 Jul 1964 | 292 mm2010 · driest 2 mm in 1894 | 133 |
| August | 42.2°C18 Aug 1936 | -0.6°C30 Aug 1915 | 133 mm19 Aug 1924 | 345 mm1993 · driest 10 mm in 2003 | 131 |
| September | 38.3°C7 Sep 1939 | -7.2°C30 Sep 1899 | 105 mm21 Sep 1950 | 359 mm1965 · driest 8 mm in 1953 | 131 |
| October | 35.0°C5 Oct 1963 | -20.6°C30 Oct 1925 | 59 mm6 Oct 1914 | 158 mm2019 · driest 1 mm in 1960 | 131 |
| November | 26.1°C1 Nov 1938 | -25.0°C26 Nov 1977 | 62 mm23 Nov 1931 | 192 mm1931 · driest 0 mm in 1976 | 132 |
| December | 21.1°C16 Dec 2021 | -35.0°C26 Dec 1914 | 54 mm14 Dec 2015 | 141 mm2015 · driest 0 mm in 1958 | 132 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 30 | <1 | 5 |
| February | 0 | 0 | 27 | <1 | 4 |
| March | <1 | 0 | 24 | 2 | 2 |
| April | 2 | <1 | 11 | 3 | <1 |
| May | 9 | 2 | 1 | 4 | <1 |
| June | 20 | 7 | 0 | 5 | 0 |
| July | 26 | 11 | 0 | 4 | 0 |
| August | 24 | 6 | 0 | 4 | 0 |
| September | 14 | 3 | <1 | 3 | 0 |
| October | 3 | <1 | 9 | 2 | 0 |
| November | <1 | 0 | 22 | 2 | 1 |
| December | 0 | 0 | 30 | 1 | 4 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 15% | 3% | 9% | -7.6–1.1°C |
| February | <1% | 16% | 3% | 11% | -5.0–3.5°C |
| March | 5% | 21% | 6% | 19% | 2.0–10.7°C |
| April | 22% | 27% | 10% | 32% | 11.6–18.4°C |
| May | 47% | 31% | 12% | 39% | 19.5–24.8°C |
| June | 65% | 32% | 13% | 38% | 24.4–28.8°C |
| July | 75% | 25% | 11% | 24% | 27.2–31.6°C |
| August | 74% | 25% | 10% | 26% | 25.9–30.0°C |
| September | 62% | 24% | 10% | 25% | 21.6–26.2°C |
| October | 32% | 20% | 7% | 18% | 14.6–20.3°C |
| November | 3% | 17% | 5% | 13% | 3.7–10.7°C |
| December | 0% | 16% | 3% | 10% | -4.5–3.4°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 4846565
- NOAA station
- USC00134142 · IOWA FALLS
- Station distance
- 10 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 29 usable years
- Daylight
- Calculated from latitude 42.52°, 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.