United States · 1991–2020

Best time to visit
Galesburg.

September leads for comfortable weather in Galesburg: typically 24.7°C by day, 11.4°C at night, with 98 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember
Typical high24.7°C
Typical low11.4°C
Rain in September98 mm
Comfort

September

September · June · August

77climate match
Beach

July

July · August · June

68climate match
Outdoors

May

May · October · September

67climate match

The weakest month is January, scoring 5 against September’s 77days reach only 0.7°C, 23° 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
50.7° / -7.4°
Feb
52.7° / -7.3°
Mar
129.2° / -2.3°
Apr
3816.2° / 3°
May
6822.9° / 9.2°
Jun
7027.9° / 14.2°
Jul
6529.8° / 16.2°
Aug
6928.3° / 15.5°
Sep
7724.7° / 11.4°
Oct
4817.8° / 5.9°
Nov
139.4° / 0.6°
Dec
52.9° / -5.1°
Monthly climate evidence for Galesburg — daylight is calculated from latitude, everything else is measured
MonthDayNightRainWet daysDaylightComfortCoverage
January0.7°C-7.4°C69 mm11.39 h 245Strong coverage
February2.7°C-7.3°C50 mm8.210 h 305Good coverage
March9.2°C-2.3°C63 mm811 h 4812Strong coverage
April16.2°C3°C96 mm1013 h 1838Strong coverage
May22.9°C9.2°C111 mm10.714 h 3468Strong coverage
June27.9°C14.2°C107 mm9.315 h 1570Strong coverage
July29.8°C16.2°C102 mm7.714 h 5965Strong coverage
August28.3°C15.5°C113 mm9.113 h 5369Strong coverage
September24.7°C11.4°C98 mm8.812 h 2677Strong coverage
October17.8°C5.9°C99 mm10.210 h 5948Strong coverage
November9.4°C0.6°C78 mm10.39 h 4313Strong coverage
December2.9°C-5.1°C72 mm10.59 h 065Good coverage

What has changed

Galesburg runs +1.0°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
+2.0
Feb
Mar
+2.1
Apr
+0.3
May
+0.9
Jun
+1.0
Jul
+0.6
Aug
+0.2
Sep
+1.2
Oct
+0.7
Nov
+0.6
Dec
September daytime highs, 20112025. Last recorded: 25.3°C.
Records at GULL LAKE BIOLOGICAL STN, 1929–2026
MonthRecord highRecord lowWettest dayWettest / driest monthYears
January18.9°C25 Jan 1950-29.4°C30 Jan 195194 mm19 Jan 1952137 mm1952 · driest 1 mm in 202090
February21.7°C28 Feb 2024-28.3°C3 Feb 199653 mm20 Feb 2018116 mm1939 · driest 2 mm in 198789
March30.0°C21 Mar 2012-26.1°C8 Mar 194365 mm19 Mar 1948146 mm1991 · driest 0 mm in 201592
April31.1°C18 Apr 2002-15.6°C7 Apr 198274 mm19 Apr 1975214 mm2026 · driest 11 mm in 200494
May34.4°C16 May 1998-5.6°C9 May 194781 mm31 May 1989252 mm2004 · driest 15 mm in 202193
June38.9°C1 Jun 1934-2.2°C27 Jun 199292 mm26 Jun 1978236 mm1979 · driest 7 mm in 198494
July42.2°C13 Jul 19364.4°C2 Jul 2001106 mm3 Jul 2008232 mm2011 · driest 3 mm in 197594
August39.4°C5 Aug 19472.8°C7 Aug 1993139 mm19 Aug 1939265 mm1975 · driest 11 mm in 197690
September37.8°C1 Sep 1953-3.9°C29 Sep 1942154 mm14 Sep 2008357 mm2008 · driest 0 mm in 197990
October32.2°C6 Oct 1963-7.8°C27 Oct 197677 mm5 Oct 1941249 mm1941 · driest 6 mm in 195292
November26.1°C1 Nov 1950-21.7°C25 Nov 195060 mm5 Nov 1990193 mm1990 · driest 10 mm in 196291
December20.6°C5 Dec 2001-26.1°C31 Dec 197649 mm31 Dec 2019148 mm1984 · driest 8 mm in 194387
Typical days per month at GULL LAKE BIOLOGICAL STN, 1991–2020
MonthDays 25°C+Days 30°C+Frost nightsHeavy rain (10 mm+)Snow days
January002529
February002416
March<1<11922
April3<193<1
May113140
June2311040
July2714030
August269030
September155<130
October4<143<1
November001422
December002527
How often, not how much — every day in GULL LAKE BIOLOGICAL STN’s record sorted by what it was actually like, rather than averaged
MonthWarm & dry daysWet daysWashoutsWeek with 3+ wet daysDaytime mean has ranged
January0%32%4%37%-3.4–3.0°C
February0%28%5%29%-1.7–5.6°C
March4%28%7%35%3.6–11.6°C
April17%34%10%43%12.2–18.1°C
May47%32%12%38%18.7–24.9°C
June67%31%12%36%24.8–29.3°C
July76%25%10%26%27.5–31.3°C
August74%26%10%28%26.3–30.0°C
September61%28%10%31%22.4–26.0°C
October28%29%9%36%15.2–20.0°C
November3%33%8%41%5.7–11.8°C
December0%32%6%39%-1.3–5.1°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.

1934Each stripe is one year’s mean temperature against the 69-year average. Warmest: 1998. Coolest: 1940.2008

The evidence behind this page

Nearby, measured,
and named.

Place identity
GeoNames 4993609
NOAA station
USC00203504 · GULL LAKE BIOLOGICAL STN
Station distance
12 km from the place centre
Climate period
1991–2020
Minimum month coverage
20 usable years
Daylight
Calculated from latitude 42.29°, 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.

These places read the same station, so their numbers are identical — distance from GULL LAKE BIOLOGICAL STN is what differs

Stony PointSouth Gull LakeAugustaDeltonRichlandHickory Corners