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Climate in Broomfield · NOAA 1991–2020 normals

Broomfield’s winters are colder and snowier than most of the U.S.

A typical July afternoon reaches 89°, a January night drops to 19°, and about 74 inches of snow falls in a normal winter.

More snow than 93% of U.S. towns#27Snowiest  of 148 in CO
Colder January nights than 63% of U.S. towns#128 coldest of 149 in CO
All CO rankings →

A year in Broomfield at a glance

Each month’s typical high and low, and what it brings.

Jan46°19° 9" snow
Feb47°21° 12" snow
Mar56°28° 16" snow
Apr62°34° 8" snow
May71°44° Last frost ~May 22 days 90°+
Jun83°53° 10 days 90°+
Jul89°58° 19 days 90°+
Aug87°56° 16 days 90°+
Sep79°48° 6 days 90°+
Oct66°36° First frost ~Oct 115" snow
Nov now54°27° 8" snow
Dec46°19° 12" snow

What stands out about Broomfield’s climate

Compared with towns across the U.S., with Broomfield’s place in Colorado beside it.

A normal year

What a year in Broomfield feels like

Typical highs and lows by season and by month, from NOAA’s 30-year normals.

Winter
46° / 20°
19 days with 1"+ of snow
Spring
63° / 35°
Last frost around May 2
Summer
86° / 56°
53 days reach 90°
Fall
66° / 37°
First frost around Oct 11
Best months to be outsideMayJunSepHighs of 62–84° and lows of 40° or more
Frost, heat & the growing season

About 160 frost-free days a year

In half of years the last 32° night comes by May 2 and the first by October 11. Frost and day counts come from NOAA’s station at Northglenn, CO, 4 miles from the city’s center point, at about the same height.

149
nights at or below 32° in a normal year
120th most of 149 in Colorado
More freezing nights than 84% of U.S. towns
4
nights at or below 0°
134th most of 149 in Colorado
More nights at or below 0° than 63% of U.S. towns
53
days that reach 90°
26th most of 149 in Colorado
More 90° days than 76% of U.S. towns
6
days that reach 100°
21st most of 149 in Colorado
More 100° days than 87% of U.S. towns
6aUSDA zone
Plant hardiness zone 6a

The 2023 USDA map puts Broomfield’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −8°. Plant labels use the zone; frost dates tell you when to plant.

Freezing nights by month

Average nights at or below 32°

29
JFMAMJJASOND

90° days by month

Average days at 90° or more

19
JFMAMJJASOND
Rain & snow

About 74 inches of snow a winter

Snow, measured at Broomfield 1.1 Ne, CO, falls mostly in March. Precipitation (rain plus melted snow) adds up to 16 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 87 days a year.

16"
Rain + melted snow a year
87th driest of 149 in Colorado
Drier than 92% of U.S. towns
74"
Snow in a normal winter
27th snowiest of 148 in Colorado
More snow than 93% of U.S. towns

Rain + melted snow by month

Inches of water

2.6"
JFMAMJJASOND

Snowfall by month

Inches of snow

16"
JFMAMJJASOND
Heating & cooling

Heating and cooling a home in Broomfield

86% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.

5,449 heating degree daysMore heating than 53% of U.S. towns
879 cooling degree daysLess cooling than 53% of U.S. towns

Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Northglenn, CO.

Living here

Living with Broomfield’s climate

What the numbers mean for a garden, a free afternoon and a bad-weather day.

The garden window

160 frost-free days in zone 6a. The last frost comes by May 2 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 11.

Get outside

Months with highs of 62–84° and lows of 40° or more: May, June and September. 38 miles of trails are waiting.

Parks & trails →
Storms and extremes

Of the yearly building losses FEMA expects in Broomfield from natural hazards, river flooding is the largest share (34%); heat waves, cold waves, winter storms and ice storms together are 12%. Normals are averages; the hazards page covers the extremes.

Natural hazards →
Next door

Broomfield and its neighbors

Dacono has the coldest January nights next door (17°, 2° colder) and Dacono the hottest July afternoons (90°, 1° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.

Arvada: January low 20°, July high 88°Berkley: January low 19°, July high 89°Twin Lakes: January low 19°, July high 89°Shaw Heights: January low 20°, July high 89°Sherrelwood: January low 20°, July high 89°Federal Heights: January low 20°, July high 89°Todd Creek: January low 17°, July high 90°Welby: January low 19°, July high 89°Commerce City: January low 17°, July high 90°Leyner: January low 17°, July high 90°Paragon Estates: January low 19°, July high 88°Frederick: January low 16°, July high 90°Fort Lupton: January low 16°, July high 91°Westminster: January low 19°, July high 89°Superior: January low 20°, July high 88°Thornton: January low 18°, July high 90°Lafayette: January low 19°, July high 89°Louisville: January low 19°, July high 89°Erie: January low 18°, July high 89°Northglenn: January low 19°, July high 89°Dacono: January low 17°, July high 90°Broomfield: January low 19°, July high 89°BroomfieldWestminsterSuperiorThorntonLafayetteLouisvilleErieNorthglennDacono
ColderMilder16° to 20°
Dacono17.1° −2.2°
Erie18.1° −1.2°
Thornton18.4° about the same
Lafayette18.6° about the same
Louisville19.1° about the same
Broomfield19.3°
Northglenn19.3° about the same
Westminster19.4° about the same
Superior19.5° about the same

Climates most like Broomfield’s, farther away

TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.

TownJan. lowJuly highPrecip.Snow
Broomfield, CO19°89°16"74"
Herriman, UT22°90°15"74"
Pocatello, ID19°87°15"64"
Casper, WY15°89°12"82"
Chadron, NE14°89°18"50"

Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.

Then and now

Warmer than it used to be

The last 30 years in Broomfield averaged 1.4° warmer than the 1900s. The biggest change is in March (+3.3°).

+1.4°1991–2020 vs. 1901–2000

A bigger shift than in 56% of U.S. towns.

Winter+1.7°now 33°, was 31°
Spring+1.6°now 49°, was 48°
Summer+1.3°now 71°, was 70°
Fall+1.1°now 52°, was 51°

Change by month

JanFebMarAprMayJunJulAugSepOctNovDec

The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.

Compared with other towns

How Broomfield compares

Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Broomfield’s place among Colorado’s.

Summer heat89° July high
Hotter July afternoons than 72% of U.S. towns67th hottest of 149 in Colorado
Winter cold19° January low
Colder January nights than 63% of U.S. towns128th coldest of 149 in Colorado
Precipitation16" a year
Drier than 92% of U.S. towns87th driest of 149 in Colorado
Snow74" a winter
More snow than 93% of U.S. towns27th snowiest of 148 in Colorado
Hot days53 days at 90°+
More 90° days than 76% of U.S. towns26th most of 149 in Colorado
Freezing nights149 a year
More freezing nights than 84% of U.S. towns120th most of 149 in Colorado
Growing season160 frost-free days
A shorter frost-free season than 84% of U.S. towns119th shortest of 145 in Colorado
Month by month

Broomfield weather by month

Highs, lows and precipitation from NOAA’s grid at Broomfield’s center; snow, wet days and snow on the ground from Broomfield 1.1 Ne, CO. 1991–2020 normals.

MonthHighLowRain + meltSnowWet days30-yr range
January46°19°0.5"9.0"524° – 39°
February47°21°0.7"12.4"629° – 42°
March56°28°1.2"16.3"736° – 49°
April62°34°2.2"8.1"942° – 54°
May71°44°2.6"2.6"1151° – 62°
June83°53°1.7"0.0"863° – 73°
July89°58°1.7"0.0"969° – 77°
August87°56°1.6"0.0"967° – 75°
September79°48°1.3"0.0"758° – 68°
October66°36°1.1"5.2"644° – 57°
November54°27°0.8"8.4"532° – 47°
December46°19°0.6"11.9"525° – 36°
Year66°37°16.0"73.9"87
Year to year

How much a month can swing

A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 32° to 47°. August is the most reliable, staying within 8°.

Coldest to warmest month in 30 yearsNormal
Sources

Where Broomfield’s numbers come from

Normals are 30-year averages, not a forecast. How TownRatings reads climate data →

  • Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Broomfield’s center.
  • Snow: Broomfield 1.1 Ne, CO (NOAA station in town).
  • Frost, freezing nights, 90° and 100° days, heating and cooling: Northglenn, CO, 4 miles from the city’s center point, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
  • Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
  • Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
  • Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).

Common questions about Broomfield’s climate

What is the weather like in Broomfield?

A typical July afternoon reaches 89°, a January night drops to 19°, and about 74 inches of snow falls in a normal winter. Colder January nights than 63% of U.S. towns; hotter July afternoons than 72% of U.S. towns.

How cold does it get in Broomfield in winter?

December nights average 19°. About 149 nights a year reach 32° or below and 4 reach 0° or below. In the coldest December of the last 30 years the month averaged 25°.

How much snow does Broomfield get?

About 74 inches in a normal winter at Broomfield 1.1 Ne, CO, most of it in March.

How hot does it get in Broomfield?

July, with a typical high of 89° and a low of 58°. About 53 days a year reach 90° and 6 reach 100° (Northglenn, CO).

When is the first and last frost in Broomfield?

In half of years the last spring frost (32°) comes by May 2 and the first fall frost by October 11, about 160 frost-free days, at Northglenn, CO.

What growing zone is Broomfield in?

Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −8°.

What is the best time of year to visit Broomfield?

By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.

Is Broomfield getting warmer?

Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 56% of U.S. towns.

Neighbors talk weather

Gardens, snow, and the best days of the year in Broomfield.

Town Square →
Ask your neighbors

Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.