Last frost date in Morton, Illinois

April 21

Average last frost in spring. In an early year (1 in 10) it's over by April 7; in a late year (1 in 10) it comes after May 7.

October 17

Average first frost in fall. 1 year in 10 it comes by October 3.

Source: NOAA U.S. Climate Normals 1991–2020, station Congerville 2NW (USC00111836), 11.8 miles from Morton, elevation 640 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.

This station is also the nearest one for Washington, so its frost dates are the same as Morton's.

What to plant now

Frost dates for Morton, Illinois
Early yearAverageLate year
Last frost in springApr 7Apr 21May 7
First frost in fallOct 3Oct 17Oct 30

Frost-free days in an average year: 178

Light frost, frost and hard freeze in Morton
Chance in a yearAverage last in springAverage first in fall
Light frost (36°F)Every yearMay 2Oct 6
Frost (32°F)Every yearApr 21Oct 17
Hard freeze (28°F)Every yearApr 9Oct 27

Nights at 32°F or colder in an average year: 134

What to plant now in Morton

Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.

Nearby in Illinois

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