Photo: Dual Freq · CC BY 2.5For weather, Hammond is about as ordinary as U.S. towns get
The depth of winter brings overnight lows near 19°. In January, nights here are colder than in 66% of U.S. towns. Decade by decade the climate has edged up, 1.2° above 1901–2000. Homes need heating from November to March, the months averaging under 50°.
A year in Hammond at a glance
Each month’s typical high and low, and what it brings.
What stands out about Hammond’s climate
Compared with towns across the U.S., with Hammond’s place in Illinois beside it.
What a year in Hammond feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 187 frost-free days a year
In half of years the last 32° night comes by April 16 and the first by October 22. Frost and day counts come from NOAA’s station at Decatur Airport, 15 miles from the town’s center, at about the same height.
The 2023 USDA map puts Hammond’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −6°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 7 inches of snow a winter
Snow, measured at Hammond, IL, falls mostly in January. Precipitation (rain plus melted snow) adds up to 39 inches a year; May is the wettest month and February the driest. Rain or snow falls on about 101 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Hammond
83% of the work is heating. Months averaging under 55° run from November through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Decatur Airport.
Living with Hammond’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
187 frost-free days in zone 6a. The last frost comes by Apr 16 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 22.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Hammond from natural hazards, river flooding is the largest share (42%); heat waves, cold waves, winter storms and ice storms together are 16%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Hammond and similar climates
TownRatings has no climate map of the towns around Hammond yet.
Climates most like Hammond’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.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Hammond, IL | 19° | 86° | 39" | 6.7" |
| St. Marys, OH | 19° | 84° | 39" | 10" |
| Cameron, MO | 18° | 87° | 40" | 7.6" |
| Mission, KS | 21° | 88° | 40" | 11" |
| Wheeling, WV | 22° | 84° | 42" | 15" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Hammond averaged 1.2° warmer than the 1900s. The biggest change is in December (+2.2°).
A smaller shift than in 62% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Hammond compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Hammond’s place among Illinois’.
Hammond weather by month
Highs, lows and precipitation from NOAA’s grid at Hammond’s center; snow, wet days and snow on the ground from Hammond, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 35° | 19° | 2.2" | 3.7" | 8 | 20° – 39° |
| February | 40° | 23° | 2.0" | 1.3" | 7 | 19° – 41° |
| March | 51° | 32° | 2.7" | 0.3" | 9 | 35° – 55° |
| April | 64° | 42° | 4.2" | 0.0" | 10 | 45° – 59° |
| May | 74° | 53° | 4.5" | 0.0" | 12 | 58° – 72° |
| June | 83° | 62° | 4.4" | 0.0" | 9 | 68° – 76° |
| July | 86° | 65° | 4.0" | 0.0" | 8 | 70° – 82° |
| August | 84° | 63° | 3.2" | 0.0" | 7 | 69° – 79° |
| September | 79° | 55° | 3.0" | 0.0" | 6 | 62° – 72° |
| October | 67° | 44° | 3.3" | 0.0" | 8 | 50° – 60° |
| November | 51° | 33° | 3.3" | 0.2" | 9 | 35° – 50° |
| December | 39° | 24° | 2.3" | 1.2" | 8 | 18° – 41° |
| Year | 63° | 43° | 39.2" | 6.7" | 101 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 18° to 41°. June is the most reliable, staying within 8°.
Where Hammond’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 Hammond’s center.
- Snow: Hammond, IL (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Decatur Airport, 15 miles from the town’s center, 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 Hammond’s climate
What is the weather like in Hammond?
A typical July afternoon reaches 86°, a January night drops to 19°, and about 7 inches of snow falls in a normal winter. Colder January nights than 66% of U.S. towns; hotter July afternoons than 52% of U.S. towns.
How cold does it get in Hammond in winter?
January nights average 19°. About 113 nights a year reach 32° or below and 4 reach 0° or below. In the coldest January of the last 30 years the month averaged 20°.
How much snow does Hammond get?
About 6.7 inches in a normal winter at Hammond, IL, most of it in January.
How hot does it get in Hammond?
July, with a typical high of 86° and a low of 65°. About 27 days a year reach 90° (Decatur Airport).
When is the first and last frost in Hammond?
In half of years the last spring frost (32°) comes by April 16 and the first fall frost by October 22, about 187 frost-free days, at Decatur Airport.
What growing zone is Hammond in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −6°.
What is the best time of year to visit Hammond?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Hammond getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 62% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Hammond.
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.