Longmont weather in June

In June, Longmont sees average daytime highs of 80°F and overnight lows near 53°F, with 2.1 in of rain across 8.5 wet days and about 14.8 hours of daylight. It is the 3rd-warmest and 3rd-wettest month of the year here.

Highs climb over the month, from about 76°F in the first days to 84°F by the end. The sky is clear or mostly clear about 34% of the time in June, and the air most often feels dry.

Daylight stretches from about 14 h 36 min at the start of June to 14 h 48 min by month's end. Set against the rest of the year, June is Longmont's 10th-clearest and 4th-windiest month. For the whole year in context, see Longmont's year-round climate.

Daytime high
80°
3rd warmest
Overnight low
53°
10th coldest
Rainfall
2.1 in
8.5 wet days
Daylight
14 h 48 min
4:35 AM – 7:26 PM
Cloud cover
52%
10th clearest
Wind
5 mph
4th windiest
Solar energy
7.36 kWh/m²
Travel score
6.6
out of 10

Longmont is city in Boulder County, Colorado, United States.

Density
1,228/km²
people per km²
Founded
1871

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in June

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 76°F in the first days to 84°F by the end.

A typical June day in Longmont reaches about 80°F in the afternoon and slips back to 53°F overnight — a 28°F spread between the day's warmth and the night's chill. On most days the high lands between 69°F and 91°F. Set against its neighbours, June runs about 11°F warmer than May and about 6°F cooler than July.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17549
27549
37649
47650
57650
67750
77750
87851
97851
107851
117951
127952
137952
148052
158052
168053
178153
188153
198153
208254
218254
228254
238355
248355
258355
268455
278456
288456
298556
308556

How June really feels in Longmont

Once humidity and wind are folded in, June averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

June sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Longmont weather by month

How June compares with the rest of the year at a glance. June is the 3rd-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan41° / 18°0.84.74.59.50.1
Feb44° / 20°0.85.3510.41.0
Mar54° / 27°1.67.34.411.73.6
Apr61° / 35°2.69.54135.0
May69° / 44°3.411.70.614.26.2
Jun80° / 53°2.18.5014.86.6
Jul86° / 59°1.77.4014.65.3
Aug84° / 57°1.66.8013.66.1
Sep76° / 49°1.55.90.412.37.6
Oct63° / 37°1.66.51.910.96.2
Nov50° / 27°1.15.84.49.82.7
Dec41° / 19°0.74.54.49.20.2

Cloud cover in June

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in June.

Beyond those clear spells, partly cloudy skies cover about 30% of June, with mostly cloudy or overcast conditions the remaining 36%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15446
25545
35644
45842
55842
66040
76040
86040
96139
106139
116238
126238
136337
146436
156436
166436
176436
186535
196634
206733
216733
226931
236931
246931
257129
267129
277129
287228
297228
307228

Chance of precipitation in June

Any precipitation

Longmont gets around 2.1 in of rain over 8.5 wet days in June. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 29% and peaks near 39% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
139
238
337
437
536
635
735
834
933
1033
1132
1231
1331
1430
1529
1628
1727
1826
1925
2025
2124
2223
2323
2422
2522
2621
2721
2820
2920
3020

Humidity in June

DryComfortableHumidMuggyOppressiveMiserable

Most of June feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, June lands in the dry band about 93% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
19820
29820
39730
49730
59730
69730
79640
89640
99640
109550
119550
129460
139460
149370
159370
169280
179280
189280
199190
209190
219190
2290100
2390100
2489110
2589110
2688120
2788120
2887130
2987130
3085141

Wind in June

Winds average 5 mph in June.

Across June, daily wind ranges from about 4 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

Sunrise & sunset in June

DaylightNight

Daylight runs from about 14 h 36 min at the start of June to 14 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over June. Sunrise moves from 4:39 AM to 4:39 AM, and sunset from 7:17 PM to 7:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
114.64:397:17
214.74:387:18
314.74:387:19
414.74:387:19
514.74:377:20
614.74:377:21
714.74:377:21
814.84:367:22
914.84:367:22
1014.84:367:23
1114.84:367:24
1214.84:367:24
1314.84:367:25
1414.84:357:25
1514.84:357:25
1614.84:357:26
1714.84:357:26
1814.94:357:27
1914.94:367:27
2014.94:367:27
2114.94:367:28
2214.94:367:28
2314.94:367:28
2414.94:367:28
2514.94:377:28
2614.94:377:28
2714.94:377:29
2814.84:387:29
2914.84:387:29
3014.84:397:29

Solar energy in June

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in June, about 7.36 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.42 kWh/m² to a high of 7.36 kWh/m² in June across the year — June's 7.36 kWh/m² sits near the top of that range.

02468151015202530
Solar energy (kWh/m²)Level
17.0Intense
27.1Intense
37.1Intense
47.1Intense
57.2Intense
67.2Intense
77.2Intense
87.2Intense
97.2Intense
107.3Intense
117.3Intense
127.3Intense
137.3Intense
147.3Intense
157.3Intense
167.4Intense
177.4Intense
187.4Intense
197.4Intense
207.4Intense
217.5Intense
227.5Intense
237.5Intense
247.5Intense
257.5Intense
267.5Intense
277.5Intense
287.5Intense
297.5Intense
307.5Intense
Planning a trip in June

Is June a good time to visit Longmont?

Our two travel scores rate June for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.6
Sightseeing
2nd-best month of the year
6.8
Beach & pool
3rd-best month of the year

June is a reasonable time to visit Longmont for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Longmont in June

From June's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In June, Longmont sees daytime highs around 80°F and nights near 53°F. Pack sun protection. Worth having: light clothes and rain gear. About 9 days see rain.

sun protectionlight clothesrain gear

UV index in Longmont in June

LowModerateHighVery highExtreme

Clear-sky midday UV in June peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Longmont peaks around July 13 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 13UV 11Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar7High
Apr6High
May7Very high
Jun11Extreme
Jul11Extreme
Aug10Very high
Sep7Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Longmont in June

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where June falls, not just the annual average.

Air quality in Longmont is worst in October — around 30 µg/m³ PM2.5 (moderate), about 3.1× the cleanest month (November, 10 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodOct 1528 µg/m³Nov 2310 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb12Moderate
Mar14Moderate
Apr11Good
May11Good
Jun12Good
Jul14Moderate
Aug19Moderate
Sep17Moderate
Oct30Moderate
Nov10Good
Dec11Good
Location & terrain

Where is Longmont?

Longmont sits at 40.2°N, 105.1°W, 4,984 ft above sea level, in United States. The nearest listed city is Erie, 8.7 mi away.

Topography around Longmont

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Longmont.

Within 2 miles, the terrain around Longmont has only modest variations in elevation — a maximum elevation change of 197 ft around an average of 4,993 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,765 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,721 ft.

The land around Longmont is covered by artificial surfaces (50%) and trees (22%) within 2 miles, grassland (54%) and cropland (25%) within 10 miles, and grassland (42%) and trees (31%) within 50 miles.

2 miles
197 ft
10 miles
1,765 ft
50 miles
9,721 ft
treesgrasslandcroplandartificial surfacesbare terrainwatermoss and lichen
June weather nearby: Erie 8.7 mi · Lafayette 12 mi · Louisville 13 mi · Boulder 14 mi · Loveland 16 mi · Broomfield 17 mi · Brighton 19 mi · Northglenn 21 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Longmont (40.1672°, -105.1019°, elevation 4,984 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).