United States · 1991–2020

Best time to visit
Boulder Flats.

September leads for comfortable weather in Boulder Flats: typically 24°C by day, 3.3°C at night, with 25 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high24°C

Typical low3.3°C

Rain in September25 mm

Comfort

September

September · June · August

78climate match

Beach

July

July · August · June

63climate match

Outdoors

September

September · May · June

75climate match

The weakest month is January, scoring 5 against September’s 78 — days reach only 0.7°C, 23° below the 24°C the score treats as ideal, and nights drop to -16.5°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

50.7° / -16.5°

Feb

53.7° / -13.9°

Mar

1410.6° / -7.7°

Apr

3415.1° / -3°

May

5319.5° / 1.8°

Jun

7726.1° / 6.1°

Jul

6830.9° / 9.8°

Aug

7029.3° / 8.2°

Sep

7824° / 3.3°

Oct

4216.2° / -2.6°

Nov

58.4° / -9.3°

Dec

51.3° / -15.1°

Monthly climate evidence for Boulder Flats — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	0.7°C	-16.5°C	10 mm	2.1	9 h 20	5	Good coverage
February	3.7°C	-13.9°C	21 mm	4.1	10 h 27	5	Good coverage
March	10.6°C	-7.7°C	26 mm	4.1	11 h 47	14	Good coverage
April	15.1°C	-3°C	49 mm	5.5	13 h 20	34	Good coverage
May	19.5°C	1.8°C	72 mm	6.6	14 h 37	53	Good coverage
June	26.1°C	6.1°C	21 mm	3.5	15 h 20	77	Good coverage
July	30.9°C	9.8°C	12 mm	2.7	15 h 03	68	Good coverage
August	29.3°C	8.2°C	17 mm	3.4	13 h 56	70	Good coverage
September	24°C	3.3°C	25 mm	4.3	12 h 26	78	Good coverage
October	16.2°C	-2.6°C	29 mm	4	10 h 58	42	Good coverage
November	8.4°C	-9.3°C	13 mm	2.7	9 h 40	5	Good coverage
December	1.3°C	-15.1°C	15 mm	3	9 h 02	5	Good coverage

Records at LANDER 1W, 1999–2025
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	16.1°C19 Jan 2009	-35.0°C6 Jan 2017	20 mm2 Jan 2023	55 mm2023 · driest 1 mm in 2000	21
February	18.3°C8 Feb 2006	-36.1°C18 Feb 2006	36 mm29 Feb 2004	59 mm2004 · driest 0 mm in 2009	21
March	24.4°C31 Mar 2004	-27.2°C4 Mar 2015	33 mm29 Mar 2007	67 mm2025 · driest 2 mm in 2004	22
April	28.9°C28 Apr 2000	-17.2°C10 Apr 2013	51 mm1 Apr 2017	139 mm2017 · driest 3 mm in 2007	22
May	35.0°C29 May 2003	-10.6°C2 May 2013	85 mm8 May 2016	152 mm2008 · driest 2 mm in 2006	23
June	36.7°C28 Jun 2002	-2.2°C5 Jun 2001	30 mm18 Jun 2018	88 mm2023 · driest 0 mm in 2006	22
July	38.9°C13 Jul 2002	2.2°C28 Jul 2015	13 mm17 Jul 2018	36 mm2009 · driest 0 mm in 2011	21
August	37.8°C11 Aug 2022	0.0°C31 Aug 2005	37 mm19 Aug 2004	48 mm2004 · driest 1 mm in 2013	22
September	36.1°C5 Sep 2022	-7.8°C24 Sep 2000	36 mm27 Sep 2013	99 mm2013 · driest 0 mm in 2010	23
October	30.6°C2 Oct 2011	-23.3°C31 Oct 2002	38 mm5 Oct 2009	66 mm2009 · driest 2 mm in 2001	23
November	23.3°C13 Nov 1999	-29.4°C13 Nov 2014	31 mm24 Nov 2023	41 mm2016 · driest 0 mm in 2009	23
December	17.2°C3 Dec 2012	-35.6°C31 Dec 2014	14 mm24 Dec 2023	40 mm2007 · driest 1 mm in 2024	21

Typical days per month at LANDER 1W, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	23	<1	3
February	0	0	21	<1	5
March	0	0	23	<1	4
April	1	0	19	2	3
May	7	1	9	3	<1
June	19	8	1	<1	0
July	29	21	0	<1	0
August	26	16	<1	<1	0
September	15	4	5	<1	<1
October	2	<1	20	1	2
November	0	0	23	<1	3
December	0	0	23	<1	4

How often, not how much — every day in LANDER 1W’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%	10%	<1%	3%	-2.9–6.2°C
February	0%	14%	2%	8%	-0.7–7.0°C
March	6%	14%	2%	11%	7.6–13.0°C
April	25%	19%	6%	16%	12.5–17.6°C
May	49%	22%	7%	24%	15.3–22.4°C
June	81%	13%	3%	12%	23.4–29.0°C
July	90%	9%	<1%	5%	28.4–33.0°C
August	87%	12%	1%	5%	27.5–31.1°C
September	76%	14%	3%	12%	21.5–27.1°C
October	34%	13%	4%	9%	13.3–19.4°C
November	4%	9%	1%	4%	5.5–10.6°C
December	0%	9%	1%	3%	-2.7–4.4°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 5819364
NOAA station: USC00485392 · LANDER 1W
Station distance: 10 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 16 usable years
Daylight: Calculated from latitude 42.91°, 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 LANDER 1W is what differs

Lander→Fort Washakie→Ethete→Hudson→Milford→Wind River→

Or put two places side by side: Boulder Flats vs Lander

Best time to visitBoulder Flats.

September

July

September

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Boulder Flats.

The whole year,
without the guesswork.

Nearby, measured,
and named.