United States · 1991–2020

Best time to visit
Hillsboro.

September leads for comfortable weather in Hillsboro: typically 25.5°C by day, 12.3°C at night, with 102 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.5°C

Typical low12.3°C

Rain in September102 mm

Comfort

September

September · May · June

78climate match

Beach

August

August · July · June

73climate match

Outdoors

October

October · May · April

78climate match

The weakest month is January, scoring 5 against September’s 78 — days reach only 0.2°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

50.2° / -9.6°

Feb

53° / -7.3°

Mar

1810.1° / -1.6°

Apr

4717.4° / 4.4°

May

6922.8° / 10.5°

Jun

6827.7° / 15.7°

Jul

6129.7° / 18°

Aug

6828.9° / 16.9°

Sep

7825.5° / 12.3°

Oct

5718.3° / 5.9°

Nov

2110° / -0.7°

Dec

53° / -6.3°

Monthly climate evidence for Hillsboro — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	0.2°C	-9.6°C	34 mm	5.8	9 h 32	5	Strong coverage
February	3°C	-7.3°C	41 mm	6	10 h 34	5	Strong coverage
March	10.1°C	-1.6°C	59 mm	6.3	11 h 49	18	Strong coverage
April	17.4°C	4.4°C	91 mm	8.5	13 h 14	47	Strong coverage
May	22.8°C	10.5°C	128 mm	9.5	14 h 26	69	Strong coverage
June	27.7°C	15.7°C	133 mm	8.8	15 h 05	68	Strong coverage
July	29.7°C	18°C	111 mm	7.2	14 h 50	61	Strong coverage
August	28.9°C	16.9°C	99 mm	6.5	13 h 48	68	Strong coverage
September	25.5°C	12.3°C	102 mm	6	12 h 25	78	Strong coverage
October	18.3°C	5.9°C	70 mm	6.1	11 h 02	57	Strong coverage
November	10°C	-0.7°C	52 mm	5.3	9 h 51	21	Strong coverage
December	3°C	-6.3°C	44 mm	5.5	9 h 15	5	Strong coverage

What has changed

Hillsboro runs +0.4°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

+0.5

Feb

+0.7

Mar

+1.1

Apr

-0.8

May

-0.3

Jun

0.0

Jul

-0.5

Aug

-0.2

Sep

+1.1

Oct

+0.1

Nov

0.0

Dec

+3.0

September daytime highs, 2011–2025. Last recorded: 27.1°C.

Records at MT PLEASANT 1 SW, 1898–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	20.0°C23 Jan 1909	-32.8°C31 Jan 2019	51 mm19 Jan 1907	154 mm1916 · driest 0 mm in 1919	126
February	26.1°C28 Feb 2024	-32.8°C13 Feb 1905	51 mm9 Feb 2001	114 mm1911 · driest 1 mm in 2026	125
March	32.2°C22 Mar 2026	-26.1°C5 Mar 1960	76 mm13 Mar 2006	155 mm1990 · driest 4 mm in 1981	126
April	33.3°C10 Apr 1930	-12.8°C6 Apr 1982	107 mm24 Apr 1950	279 mm1973 · driest 4 mm in 2018	126
May	38.9°C31 May 1934	-5.0°C7 May 1931	102 mm14 May 2001	348 mm2019 · driest 27 mm in 1923	127
June	38.9°C25 Jun 1988	2.2°C22 Jun 1902	183 mm10 Jun 1905	363 mm2010 · driest 8 mm in 2016	125
July	45.6°C15 Jul 1936	6.1°C4 Jul 1967	94 mm3 Jul 1931	335 mm1992 · driest 2 mm in 1936	126
August	42.2°C9 Aug 1934	3.3°C31 Aug 1915	155 mm29 Aug 2018	288 mm1980 · driest 0 mm in 2013	127
September	38.3°C15 Sep 1939	-5.0°C28 Sep 1942	141 mm13 Sep 1961	323 mm2008 · driest 4 mm in 1940	127
October	35.6°C2 Oct 1953	-12.8°C28 Oct 1925	86 mm10 Oct 1954	244 mm1941 · driest 2 mm in 2022	127
November	27.2°C1 Nov 1933	-20.6°C29 Nov 1976	72 mm1 Nov 1984	167 mm1991 · driest 0 mm in 1999	126
December	23.3°C16 Dec 2021	-31.7°C23 Dec 1989	64 mm26 Dec 1942	141 mm1982 · driest 4 mm in 1900	127

Typical days per month at MT PLEASANT 1 SW, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	28	<1	4
February	0	0	24	1	4
March	<1	0	20	2	2
April	4	<1	7	3	<1
May	12	2	<1	4	0
June	23	9	0	4	0
July	27	14	0	4	0
August	26	11	0	3	0
September	16	6	<1	3	0
October	5	<1	5	2	<1
November	<1	0	16	2	<1
December	0	0	26	2	3

The best month has moved. On the 1961–1990 numbers the strongest month here was May (scoring 81); on 2011–2025 it is September (81). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in MT PLEASANT 1 SW’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	<1%	17%	4%	10%	-4.0–4.0°C
February	<1%	18%	4%	14%	-1.9–6.9°C
March	9%	22%	7%	23%	5.7–13.2°C
April	28%	28%	10%	32%	14.5–20.1°C
May	55%	30%	11%	35%	20.5–26.3°C
June	71%	28%	13%	31%	25.9–30.2°C
July	77%	23%	11%	22%	28.3–33.0°C
August	78%	22%	10%	20%	27.5–31.8°C
September	69%	22%	11%	22%	23.3–27.9°C
October	41%	19%	7%	17%	16.2–21.9°C
November	7%	18%	6%	13%	6.7–13.1°C
December	<1%	17%	5%	13%	-1.2–6.2°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.

1899Each stripe is one year’s mean temperature against the 116-year average. Warmest: 1921. Coolest: 2014.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4860683
NOAA station: USC00135796 · MT PLEASANT 1 SW
Station distance: 17.6 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 29 usable years
Daylight: Calculated from latitude 40.84°, 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 MT PLEASANT 1 SW is what differs

Mount Pleasant→New London→Salem→Lockridge→Olds→Rome→

Or put two places side by side: Hillsboro vs Mount Pleasant

Best time to visitHillsboro.