Longmont weather in April

In April, Longmont sees average daytime highs of 61°F and overnight lows near 35°F, with 2.6 in of precipitation across 9.5 wet days and about 13 hours of daylight. It is the 7th-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 58°F in the first days to 63°F by the end. The sky is clear or mostly clear about 28% of the time in April, and the air most often feels dry.

Daylight stretches from about 12 h 24 min at the start of April to 13 h 36 min by month's end. Set against the rest of the year, April is Longmont's 11th-clearest and 1st-windiest month. For the whole year in context, see Longmont's year-round climate.

Daytime high: 61°; 7th warmest
Overnight low: 35°; 6th coldest
Precipitation: 2.6 in; 9.5 wet days
Daylight: 13 h 06 min; 5:29 AM – 6:32 PM
Cloud cover: 59%; 11th clearest
Wind: 5 mph; 1st windiest
Solar energy: 6.14 kWh/m²
Travel score: 5.0; 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.

← March Longmont year-round climate May →Best places to visit in April

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in April

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 58°F in the first days to 63°F by the end.

A typical April day in Longmont reaches about 61°F in the afternoon and slips back to 35°F overnight — a 26°F spread between the day's warmth and the night's chill. On most days the high lands between 45°F and 75°F. Set against its neighbours, April runs about 7°F warmer than March and about 9°F cooler than May.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°F)	58	58	58	59	59	59	59	59	60	60	60	60	60	60	61	61	61	61	61	61	62	62	62	62	62	63	63	63	63	64
Avg low (°F)	31	31	31	32	32	32	33	33	33	33	33	34	34	34	34	35	35	35	35	36	36	36	36	37	37	37	37	38	38	38

	Avg high (°F)	Avg low (°F)
1	58	31
2	58	31
3	58	31
4	59	32
5	59	32
6	59	32
7	59	33
8	59	33
9	60	33
10	60	33
11	60	33
12	60	34
13	60	34
14	60	34
15	61	34
16	61	35
17	61	35
18	61	35
19	61	35
20	61	36
21	62	36
22	62	36
23	62	36
24	62	37
25	62	37
26	63	37
27	63	37
28	63	38
29	63	38
30	64	38

How April really feels in Longmont

Once humidity and wind are folded in, April averages 0 days that feel above 90°F and 23 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F

heat index over the day's high

Days feeling ≤ 32°F

wind chill below the day's low

The story in April is cold — wind chill drags the overnight "feels like" below the raw low.

Longmont weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 2nd-wettest month here — the current month is highlighted below.

Month	High / Low (°F)	Rainfall (inches)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	41° / 18°	0.8	4.7	4.5	9.5	0.1
Feb	44° / 20°	0.8	5.3	5	10.4	1.0
Mar	54° / 27°	1.6	7.3	4.4	11.7	3.6
Apr	61° / 35°	2.6	9.5	4	13	5.0
May	69° / 44°	3.4	11.7	0.6	14.2	6.2
Jun	80° / 53°	2.1	8.5	0	14.8	6.6
Jul	86° / 59°	1.7	7.4	0	14.6	5.3
Aug	84° / 57°	1.6	6.8	0	13.6	6.1
Sep	76° / 49°	1.5	5.9	0.4	12.3	7.6
Oct	63° / 37°	1.6	6.5	1.9	10.9	6.2
Nov	50° / 27°	1.1	5.8	4.4	9.8	2.7
Dec	41° / 19°	0.7	4.5	4.4	9.2	0.2

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 21% of April, with mostly cloudy or overcast conditions the remaining 52%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	52	51	51	51	50	50	49	48	48	48	47	47	47	47	46	47	46	46	47	47	47	47	48	48	48	48	49	50	49	49
Cloudier (%)	48	49	49	49	50	50	51	52	52	52	53	53	53	53	54	53	54	54	53	53	53	53	52	52	52	52	51	50	51	51

	Clearer (%)	Cloudier (%)
1	52	48
2	51	49
3	51	49
4	51	49
5	50	50
6	50	50
7	49	51
8	48	52
9	48	52
10	48	52
11	47	53
12	47	53
13	47	53
14	47	53
15	46	54
16	47	53
17	46	54
18	46	54
19	47	53
20	47	53
21	47	53
22	47	53
23	48	52
24	48	52
25	48	52
26	48	52
27	49	51
28	50	50
29	49	51
30	49	51

Chance of precipitation in April

Any precipitationSnow

Longmont gets around 2.6 in of rain and snow over 9.5 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 32% and peaks near 37% on the wettest days, and about 4 days bring snow. The odds climb toward the end of the month.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	30	29	29	29	28	28	28	27	27	27	28	28	28	29	29	30	31	32	33	33	34	35	36	36	37	37	37	37	37	37
Snow chance (%)	16	16	16	16	16	15	15	15	15	14	14	13	13	13	13	12	12	12	12	11	11	11	11	11	10	10	10	9	9	8

	Rain chance (%)	Snow chance (%)
1	30	16
2	29	16
3	29	16
4	29	16
5	28	16
6	28	15
7	28	15
8	27	15
9	27	15
10	27	14
11	28	14
12	28	13
13	28	13
14	29	13
15	29	13
16	30	12
17	31	12
18	32	12
19	33	12
20	33	11
21	34	11
22	35	11
23	36	11
24	36	11
25	37	10
26	37	10
27	37	10
28	37	9
29	37	9
30	37	8

Humidity in April

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, April lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

Wind in April

Winds average 5 mph in April, the windiest month of the year.

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

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (mph)	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (mph)	Feels
1	5	calm
2	5	calm
3	5	calm
4	5	calm
5	5	calm
6	5	calm
7	5	calm
8	5	calm
9	5	calm
10	5	calm
11	5	calm
12	5	calm
13	5	calm
14	5	calm
15	5	calm
16	5	calm
17	5	calm
18	5	calm
19	5	calm
20	5	calm
21	5	calm
22	5	calm
23	5	calm
24	5	calm
25	5	calm
26	5	calm
27	5	calm
28	5	calm
29	5	calm
30	5	calm

Sunrise & sunset in April

DaylightNight

Daylight runs from about 12 h 24 min at the start of April to 13 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 72 minutes over April. Sunrise moves from 5:53 AM to 5:08 AM, and sunset from 6:17 PM to 6:47 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	12.4	12.4	12.5	12.5	12.6	12.6	12.7	12.7	12.8	12.8	12.8	12.9	12.9	13.0	13.0	13.1	13.1	13.1	13.2	13.2	13.3	13.3	13.4	13.4	13.4	13.5	13.5	13.6	13.6	13.6
Sunrise (AM)	5:53	5:51	5:50	5:48	5:47	5:45	5:43	5:42	5:40	5:38	5:37	5:35	5:34	5:32	5:30	5:29	5:27	5:26	5:24	5:23	5:21	5:20	5:18	5:17	5:15	5:14	5:13	5:11	5:10	5:08
Sunset (PM)	6:17	6:18	6:19	6:20	6:21	6:22	6:23	6:24	6:25	6:26	6:27	6:28	6:29	6:30	6:31	6:32	6:34	6:35	6:36	6:37	6:38	6:39	6:40	6:41	6:42	6:43	6:44	6:45	6:46	6:47

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.4	5:53	6:17
2	12.4	5:51	6:18
3	12.5	5:50	6:19
4	12.5	5:48	6:20
5	12.6	5:47	6:21
6	12.6	5:45	6:22
7	12.7	5:43	6:23
8	12.7	5:42	6:24
9	12.8	5:40	6:25
10	12.8	5:38	6:26
11	12.8	5:37	6:27
12	12.9	5:35	6:28
13	12.9	5:34	6:29
14	13.0	5:32	6:30
15	13.0	5:30	6:31
16	13.1	5:29	6:32
17	13.1	5:27	6:34
18	13.1	5:26	6:35
19	13.2	5:24	6:36
20	13.2	5:23	6:37
21	13.3	5:21	6:38
22	13.3	5:20	6:39
23	13.4	5:18	6:40
24	13.4	5:17	6:41
25	13.4	5:15	6:42
26	13.5	5:14	6:43
27	13.5	5:13	6:44
28	13.6	5:11	6:45
29	13.6	5:10	6:46
30	13.6	5:08	6:47

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 6.14 kWh/m².

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 — April's 6.14 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	5.7	5.8	5.8	5.8	5.9	5.9	5.9	6.0	6.0	6.0	6.1	6.1	6.1	6.1	6.2	6.2	6.2	6.2	6.2	6.2	6.3	6.3	6.3	6.3	6.3	6.3	6.4	6.4	6.4	6.4
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense

	Solar energy (kWh/m²)	Level
1	5.7	Bright
2	5.8	Bright
3	5.8	Bright
4	5.8	Bright
5	5.9	Bright
6	5.9	Bright
7	5.9	Bright
8	6.0	Bright
9	6.0	Intense
10	6.0	Intense
11	6.1	Intense
12	6.1	Intense
13	6.1	Intense
14	6.1	Intense
15	6.2	Intense
16	6.2	Intense
17	6.2	Intense
18	6.2	Intense
19	6.2	Intense
20	6.2	Intense
21	6.3	Intense
22	6.3	Intense
23	6.3	Intense
24	6.3	Intense
25	6.3	Intense
26	6.3	Intense
27	6.4	Intense
28	6.4	Intense
29	6.4	Intense
30	6.4	Intense

Planning a trip in April

Is April a good time to visit Longmont?

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

5.0

Sightseeing

7th-best month of the year

0.7

Beach & pool

7th-best month of the year

April is a reasonable time to visit Longmont for sightseeing.

What to pack for Longmont in April

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

In April, Longmont sees daytime highs around 61°F and nights near 35°F. Pack sun protection. Worth having: a warm layer and rain gear. About 10 days see rain.

sun protectiona warm layerrain gear

UV index in Longmont in April

LowModerateHighVery highExtreme

Clear-sky midday UV in April peaks around 6 — enough to warrant sun protection. 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.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	2	4	7	6	7	11	11	10	7	5	3	2
Level	Moderate	Moderate	High	High	Very high	Extreme	Extreme	Very high	Very high	High	Moderate	Low

	UV index (midday)	Level
Jan	2	Moderate
Feb	4	Moderate
Mar	7	High
Apr	6	High
May	7	Very high
Jun	11	Extreme
Jul	11	Extreme
Aug	10	Very high
Sep	7	Very high
Oct	5	High
Nov	3	Moderate
Dec	2	Low

Air quality in Longmont in April

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where April 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).

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	12	12	14	11	11	12	14	19	17	30	10	11
Level	Good	Moderate	Moderate	Good	Good	Good	Moderate	Moderate	Moderate	Moderate	Good	Good

	PM2.5 (µg/m³)	Level
Jan	12	Good
Feb	12	Moderate
Mar	14	Moderate
Apr	11	Good
May	11	Good
Jun	12	Good
Jul	14	Moderate
Aug	19	Moderate
Sep	17	Moderate
Oct	30	Moderate
Nov	10	Good
Dec	11	Good

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

artificial surfaces 50%

10 miles

1,765 ft

grassland 54%

50 miles

9,721 ft

grassland 42%

treesgrasslandcroplandartificial surfacesbare terrainwatermoss and lichen

← March Longmont year-round climate May →Best places to visit in April

April 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

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).

	Avg high (°F)	Avg low (°F)
1	58	31
2	58	31
3	58	31
4	59	32
5	59	32
6	59	32
7	59	33
8	59	33
9	60	33
10	60	33
11	60	33
12	60	34
13	60	34
14	60	34
15	61	34
16	61	35
17	61	35
18	61	35
19	61	35
20	61	36
21	62	36
22	62	36
23	62	36
24	62	37
25	62	37
26	63	37
27	63	37
28	63	38
29	63	38
30	64	38

	Clearer (%)	Cloudier (%)
1	52	48
2	51	49
3	51	49
4	51	49
5	50	50
6	50	50
7	49	51
8	48	52
9	48	52
10	48	52
11	47	53
12	47	53
13	47	53
14	47	53
15	46	54
16	47	53
17	46	54
18	46	54
19	47	53
20	47	53
21	47	53
22	47	53
23	48	52
24	48	52
25	48	52
26	48	52
27	49	51
28	50	50
29	49	51
30	49	51

	Rain chance (%)	Snow chance (%)
1	30	16
2	29	16
3	29	16
4	29	16
5	28	16
6	28	15
7	28	15
8	27	15
9	27	15
10	27	14
11	28	14
12	28	13
13	28	13
14	29	13
15	29	13
16	30	12
17	31	12
18	32	12
19	33	12
20	33	11
21	34	11
22	35	11
23	36	11
24	36	11
25	37	10
26	37	10
27	37	10
28	37	9
29	37	9
30	37	8

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

	Avg high (°F)	Avg low (°F)
1	58	31
2	58	31
3	58	31
4	59	32
5	59	32
6	59	32
7	59	33
8	59	33
9	60	33
10	60	33
11	60	33
12	60	34
13	60	34
14	60	34
15	61	34
16	61	35
17	61	35
18	61	35
19	61	35
20	61	36
21	62	36
22	62	36
23	62	36
24	62	37
25	62	37
26	63	37
27	63	37
28	63	38
29	63	38
30	64	38

	Clearer (%)	Cloudier (%)
1	52	48
2	51	49
3	51	49
4	51	49
5	50	50
6	50	50
7	49	51
8	48	52
9	48	52
10	48	52
11	47	53
12	47	53
13	47	53
14	47	53
15	46	54
16	47	53
17	46	54
18	46	54
19	47	53
20	47	53
21	47	53
22	47	53
23	48	52
24	48	52
25	48	52
26	48	52
27	49	51
28	50	50
29	49	51
30	49	51

	Rain chance (%)	Snow chance (%)
1	30	16
2	29	16
3	29	16
4	29	16
5	28	16
6	28	15
7	28	15
8	27	15
9	27	15
10	27	14
11	28	14
12	28	13
13	28	13
14	29	13
15	29	13
16	30	12
17	31	12
18	32	12
19	33	12
20	33	11
21	34	11
22	35	11
23	36	11
24	36	11
25	37	10
26	37	10
27	37	10
28	37	9
29	37	9
30	37	8

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100

	Avg high (°F)	Avg low (°F)
1	58	31
2	58	31
3	58	31
4	59	32
5	59	32
6	59	32
7	59	33
8	59	33
9	60	33
10	60	33
11	60	33
12	60	34
13	60	34
14	60	34
15	61	34
16	61	35
17	61	35
18	61	35
19	61	35
20	61	36
21	62	36
22	62	36
23	62	36
24	62	37
25	62	37
26	63	37
27	63	37
28	63	38
29	63	38
30	64	38

	Clearer (%)	Cloudier (%)
1	52	48
2	51	49
3	51	49
4	51	49
5	50	50
6	50	50
7	49	51
8	48	52
9	48	52
10	48	52
11	47	53
12	47	53
13	47	53
14	47	53
15	46	54
16	47	53
17	46	54
18	46	54
19	47	53
20	47	53
21	47	53
22	47	53
23	48	52
24	48	52
25	48	52
26	48	52
27	49	51
28	50	50
29	49	51
30	49	51

	Rain chance (%)	Snow chance (%)
1	30	16
2	29	16
3	29	16
4	29	16
5	28	16
6	28	15
7	28	15
8	27	15
9	27	15
10	27	14
11	28	14
12	28	13
13	28	13
14	29	13
15	29	13
16	30	12
17	31	12
18	32	12
19	33	12
20	33	11
21	34	11
22	35	11
23	36	11
24	36	11
25	37	10
26	37	10
27	37	10
28	37	9
29	37	9
30	37	8

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100