Boulder weather in March

In March, Boulder sees average daytime highs of 48°F and overnight lows near 22°F, with 2.0 in of precipitation across 8.8 wet days and about 11.7 hours of daylight. It is the 8th-warmest and 7th-wettest month of the year here.

Highs climb over the month, from about 43°F in the first days to 51°F by the end. The sky is clear or mostly clear about 36% of the time in March, and the air most often feels dry.

Daylight stretches from about 11 hours at the start of March to 12 h 18 min by month's end. Set against the rest of the year, March is Boulder's 8th-clearest and 6th-windiest month. For the whole year in context, see Boulder's year-round climate.

Daytime high
48°
8th warmest
Overnight low
22°
5th coldest
Precipitation
2.0 in
8.8 wet days
Daylight
11 h 42 min
6:21 AM – 6:01 PM
Cloud cover
52%
8th clearest
Wind
5 mph
6th windiest
Solar energy
5.35 kWh/m²
Travel score
1.7
out of 10

Boulder is city in and county seat of Boulder County, Colorado, United States.

Density
1,606/km²
people per km²
Founded
1858

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

Temperature in March

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 43°F in the first days to 51°F by the end.

A typical March day in Boulder reaches about 48°F in the afternoon and slips back to 22°F overnight — a 25°F spread between the day's warmth and the night's chill. On most days the high lands between 33°F and 61°F. Set against its neighbours, March runs about 8°F warmer than February and about 6°F cooler than April.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14318
24318
34319
44419
54419
64520
74520
84620
94621
104621
114721
124722
134722
144822
154822
164823
174923
184923
194924
204924
214924
224924
235024
245024
255025
265025
275025
285025
295125
305125
315126

How March really feels in Boulder

Once humidity and wind are folded in, March averages 0 days that feel above 90°F and 31 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
31
10 feel bitter (≤ 14°F)

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

Boulder weather by month

How March compares with the rest of the year at a glance. March is the 8th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan37° / 14°0.95.75.59.50.0
Feb39° / 16°1.06.7710.40.0
Mar48° / 22°2.08.87.211.71.7
Apr54° / 29°3.111.17.9133.1
May63° / 38°4.014.93.514.24.8
Jun74° / 47°3.014.30.314.86.2
Jul80° / 53°3.014.8014.56.0
Aug78° / 52°2.814.9013.66.2
Sep71° / 44°2.19.70.912.36.8
Oct58° / 33°1.97.43.910.94.9
Nov46° / 22°1.36.45.79.81.4
Dec37° / 15°0.95.35.49.20.0

Cloud cover in March

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in March.

Beyond those clear spells, partly cloudy skies cover about 19% of March, with mostly cloudy or overcast conditions the remaining 45%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25743
35842
45842
55842
65842
75842
85842
95842
105842
115842
125842
135644
145644
155644
165644
175545
185446
195446
205347
215347
225347
235347
245248
255248
265347
275248
285149
295149
305149
315050

Chance of precipitation in March

Any precipitationSnow

Boulder gets around 2.0 in of rain and snow over 8.8 wet days in March. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 28% and peaks near 36% on the wettest days, and about 7 days bring snow. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
12625
22624
32524
42523
52523
62522
72422
82422
92422
102421
112421
122421
132421
142421
152521
162521
172621
182722
192822
202922
213023
223124
233224
243325
253425
263426
273526
283527
293627
303627
313527

Humidity in March

DryComfortableHumidMuggyOppressiveMiserable

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

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

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in March

Winds average 5 mph in March.

Across March, 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.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in March

DaylightNight

Daylight runs from about 11 hours at the start of March to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 78 minutes over March. Sunrise moves from 6:44 AM to 5:56 AM, and sunset from 5:45 PM to 6:17 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.06:445:45
211.16:435:46
311.16:415:47
411.16:405:48
511.26:385:49
611.26:375:50
711.36:355:51
811.36:335:52
911.46:325:53
1011.46:305:55
1111.46:295:56
1211.56:275:57
1311.56:255:58
1411.66:245:59
1511.66:226:00
1611.76:216:01
1711.76:196:02
1811.86:176:03
1911.86:166:04
2011.96:146:05
2111.96:126:06
2211.96:116:07
2312.06:096:08
2412.06:076:09
2512.16:066:10
2612.16:046:11
2712.26:026:12
2812.26:016:13
2912.35:596:14
3012.35:576:16
3112.35:566:17

Solar energy in March

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in March, about 5.35 kWh/m².

For context, solar energy here swings from a low near 2.56 kWh/m² to a high of 7.49 kWh/m² in June across the year — March's 5.35 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.8Bright
44.8Bright
54.9Bright
64.9Bright
75.0Bright
85.0Bright
95.1Bright
105.1Bright
115.2Bright
125.2Bright
135.2Bright
145.3Bright
155.3Bright
165.4Bright
175.4Bright
185.4Bright
195.5Bright
205.5Bright
215.5Bright
225.6Bright
235.6Bright
245.7Bright
255.7Bright
265.7Bright
275.8Bright
285.8Bright
295.8Bright
305.9Bright
315.9Bright
Planning a trip in March

Hazard calendar for Boulder

In seasonPeak

In March, Boulder sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Boulder's rainy season runs March–October, when most of the year's rain falls.

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

Is March a good time to visit Boulder?

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

1.7
Sightseeing
8th-best month of the year
0.0
Beach & pool
8th-best month of the year

March is a weaker month for outdoor sightseeing in Boulder.

What to pack for Boulder in March

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

In March, Boulder sees daytime highs around 48°F and nights near 22°F. Pack a warm layer. Worth having: a heavy coat, rain gear and sun protection. About 9 days see rain.

a warm layera heavy coatrain gearsun protection

UV index in Boulder in March

LowModerateHighVery highExtreme

Clear-sky midday UV in March peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Boulder 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 Boulder in March

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Boulder is worst in August — around 21 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (May, 13 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateAug 1620 µg/m³May 1113 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb15Moderate
Mar16Moderate
Apr13Moderate
May13Moderate
Jun14Moderate
Jul14Moderate
Aug21Moderate
Sep13Moderate
Oct15Moderate
Nov15Moderate
Dec16Moderate
Location & terrain

Where is Boulder?

Boulder sits at 40.0°N, 105.3°W, 5,328 ft above sea level, in United States. The nearest listed city is Louisville, 8.1 mi away.

Topography around Boulder

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

Within 2 miles, the terrain around Boulder has significant variations in elevation — a maximum elevation change of 1,703 ft around an average of 5,495 ft above sea level; within 10 miles, very significant variations in elevation — a maximum elevation change of 4,147 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,623 ft.

The land around Boulder is covered by trees (45%) and artificial surfaces (39%) within 2 miles, grassland (44%) and trees (41%) within 10 miles, and trees (41%) and grassland (34%) within 50 miles.

2 miles
1,703 ft
10 miles
4,147 ft
50 miles
9,623 ft
treesgrasslandcroplandartificial surfacesbare terrainwatermoss and lichen
March weather nearby: Louisville 8.1 mi · Lafayette 9.9 mi · Broomfield 12 mi · Erie 12 mi · Longmont 14 mi · Westminster 17 mi · Northglenn 17 mi · Arvada 17 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 Boulder (40.015°, -105.2706°, elevation 5,328 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).