United States · 1991–2020

Best time to visit
Arapahoe.

September leads for comfortable weather in Arapahoe: typically 23.3°C by day, 7.4°C at night, with 17 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high23.3°C

Typical low7.4°C

Rain in September17 mm

Comfort

September

September · June · August

84climate match

Beach

August

August · July · June

74climate match

Outdoors

September

September · May · June

85climate match

The weakest month is January, scoring 5 against September’s 84 — days reach only -0.6°C, 25° below the 24°C the score treats as ideal, and nights drop to -12.5°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

5-0.6° / -12.5°

Feb

52° / -10.4°

Mar

169.3° / -4.5°

Apr

3613.7° / -0.6°

May

6019.2° / 4.5°

Jun

8326° / 9.5°

Jul

7331.5° / 14°

Aug

7729.7° / 12.6°

Sep

8423.3° / 7.4°

Oct

4114.3° / 0.3°

Nov

56.3° / -6.6°

Dec

5-0.9° / -12.6°

Monthly climate evidence for Arapahoe — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-0.6°C	-12.5°C	5 mm	1.4	9 h 20	5	Good coverage
February	2°C	-10.4°C	11 mm	2.8	10 h 27	5	Good coverage
March	9.3°C	-4.5°C	16 mm	2.4	11 h 47	16	Good coverage
April	13.7°C	-0.6°C	35 mm	5.7	13 h 20	36	Good coverage
May	19.2°C	4.5°C	51 mm	6.2	14 h 37	60	Good coverage
June	26°C	9.5°C	21 mm	3.7	15 h 20	83	Good coverage
July	31.5°C	14°C	12 mm	2.3	15 h 03	73	Good coverage
August	29.7°C	12.6°C	11 mm	2.8	13 h 56	77	Good coverage
September	23.3°C	7.4°C	17 mm	3.1	12 h 26	84	Good coverage
October	14.3°C	0.3°C	20 mm	3.9	10 h 58	41	Good coverage
November	6.3°C	-6.6°C	9 mm	2.4	9 h 40	5	Good coverage
December	-0.9°C	-12.6°C	7 mm	1.9	9 h 01	5	Good coverage

Records at RIVERTON, 1996–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	17.2°C1 Jan 1997	-35.0°C31 Jan 2023	16 mm11 Jan 2023	37 mm2023 · driest 0 mm in 1999	29
February	16.7°C23 Feb 2002	-33.2°C18 Feb 2006	16 mm23 Feb 2017	28 mm2024 · driest 0 mm in 2009	29
March	27.8°C25 Mar 2026	-24.9°C10 Mar 2022	67 mm31 Mar 2017	94 mm2017 · driest 0 mm in 2004	29
April	29.4°C24 Apr 2012	-16.6°C13 Apr 2022	26 mm30 Apr 2018	84 mm2016 · driest 3 mm in 2007	29
May	33.9°C29 May 2003	-7.2°C9 May 2002	51 mm26 May 2008	135 mm2011 · driest 5 mm in 2006	29
June	37.8°C15 Jun 2021	0.0°C4 Jun 1998	27 mm12 Jun 2010	97 mm2023 · driest 0 mm in 2012	28
July	40.0°C12 Jul 2026	4.4°C7 Jul 2010	16 mm25 Jul 2007	43 mm2007 · driest 0 mm in 2016	29
August	37.2°C20 Aug 2025	2.2°C31 Aug 2020	18 mm15 Aug 2009	35 mm2023 · driest 0 mm in 2020	28
September	37.8°C4 Sep 2022	-6.1°C27 Sep 1996	28 mm11 Sep 2019	50 mm2016 · driest 0 mm in 2010	28
October	28.9°C1 Oct 2005	-22.7°C30 Oct 2019	28 mm11 Oct 2023	72 mm1998 · driest 1 mm in 2001	28
November	21.7°C2 Nov 2025	-23.9°C12 Nov 2000	18 mm23 Nov 2023	27 mm2023 · driest 1 mm in 2009	28
December	17.8°C24 Dec 2025	-34.9°C22 Dec 2022	12 mm25 Dec 2016	20 mm2022 · driest 0 mm in 1998	28

Typical days per month at RIVERTON, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	31	0	3
February	0	0	28	<1	4
March	0	0	27	<1	2
April	<1	0	17	<1	3
May	6	<1	4	2	1
June	18	8	<1	<1	0
July	29	24	0	<1	0
August	28	18	0	<1	0
September	14	4	2	<1	<1
October	2	0	15	<1	2
November	0	0	28	0	3
December	0	0	31	0	5

How often, not how much — every day in RIVERTON’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	0%	5%	<1%	<1%	-4.8–3.8°C
February	0%	10%	<1%	4%	-2.8–6.4°C
March	5%	9%	1%	5%	5.6–12.5°C
April	18%	19%	3%	17%	10.9–16.0°C
May	47%	20%	5%	20%	16.2–21.5°C
June	82%	12%	2%	11%	23.1–29.7°C
July	92%	8%	1%	5%	29.2–33.3°C
August	90%	10%	1%	3%	27.9–31.4°C
September	74%	10%	1%	8%	21.2–26.0°C
October	21%	13%	2%	7%	12.1–17.6°C
November	1%	8%	<1%	2%	3.6–9.5°C
December	0%	5%	<1%	1%	-4.6–4.5°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.

1997Each stripe is one year’s mean temperature against the 27-year average. Warmest: 2012. Coolest: 2023.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5817340
NOAA station: USW00024061 · RIVERTON
Station distance: 11.6 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 21 usable years
Daylight: Calculated from latitude 42.96°, 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 RIVERTON is what differs

Midvale→

Or put two places side by side: Arapahoe vs Midvale

Best time to visitArapahoe.

September

August

September

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Arapahoe.

The whole year,
without the guesswork.

Nearby, measured,
and named.