What is the hottest month in Smithboro, IL?

July is the warmest month, with a normal high of 87°F at Vandalia.

What is the coldest month in Smithboro, IL?

January is the coldest month, with a normal low of 21°F.

What is the wettest month in Smithboro, IL?

May has the most precipitation on average, about 5.30 inches.

Checked Oct 25, 2026

Smithboro, IL Climate

1991 to 2020 normals at Vandalia, 14 mi from the center of Smithboro, elevation 490 ft.

Average weather by month

Select a month for daily normals and last year's weather

Month	High	Low	Precip.	Snow
January	37°	21°	2.97 in	--
February	42°	24°	2.49 in	--
March	53°	33°	3.32 in	--
April	65°	43°	4.86 in	--
May	75°	54°	5.30 in	--
June	84°	63°	4.87 in	--
July	87°	67°	3.90 in	--
August	86°	64°	3.24 in	--
September	80°	56°	3.07 in	--
October	68°	44°	3.26 in	--
November	54°	34°	3.76 in	--
December	42°	26°	2.69 in	--
Year	64°		43.73 in	--

Frequently asked questions

What is the hottest month in Smithboro, IL?: July is the warmest month, with a normal high of 87°F at Vandalia.
What is the coldest month in Smithboro, IL?: January is the coldest month, with a normal low of 21°F.
What is the wettest month in Smithboro, IL?: May has the most precipitation on average, about 5.30 inches.

Today

Smithboro, IL forecast

Data sources

U.S. Climate Normals 1991-2020NOAA National Centers for Environmental Information · Official site
U.S. Climate Normals 1991-2020 (daily) and GHCN-Daily via Access Data ServiceNOAA National Centers for Environmental Information · Official site

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About this data

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Climate normals are 30-year averages measured at one weather station, which may be miles from the place named here or at a different elevation.

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