Mount Vernon weather in March

In March, Mount Vernon sees average daytime highs of 56°F and overnight lows near 38°F, with 4.1 in of precipitation across 10.8 wet days and about 11.7 hours of daylight. It is the 8th-warmest and 3rd-wettest month of the year here.

Highs climb over the month, from about 51°F in the first days to 61°F by the end. The sky is clear or mostly clear about 30% of the time in March, and the air most often feels dry.

Daylight stretches from about 11 h 06 min at the start of March to 12 h 18 min by month's end. Set against the rest of the year, March is Mount Vernon's 9th-clearest and 2nd-windiest month. For the whole year in context, see Mount Vernon's year-round climate.

Daytime high
56°
8th warmest
Overnight low
38°
4th coldest
Precipitation
4.1 in
10.8 wet days
Daylight
11 h 42 min
6:15 AM – 5:56 PM
Cloud cover
63%
9th clearest
Wind
8 mph
2nd windiest
Solar energy
4.11 kWh/m²
Travel score
3.7
out of 10

Mount Vernon is city located near the center of Jefferson County, Illinois, United States.

Density
396/km²
people per km²
Founded
1817

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 51°F in the first days to 61°F by the end.

A typical March day in Mount Vernon reaches about 56°F in the afternoon and slips back to 38°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 41°F and 72°F. Set against its neighbours, March runs about 11°F warmer than February and about 11°F cooler than April.

20°40°60°80°151015202531
Avg high (°F)Avg low (°F)
15033
25133
35134
45134
55234
65235
75335
85335
95336
105436
115437
125537
135538
145538
155638
165639
175639
185740
195740
205840
215841
225841
235941
245942
256042
266042
276042
286143
296143
306243
316244

How March really feels in Mount Vernon

Once humidity and wind are folded in, March averages 0 days that feel above 90°F and 14 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
14
wind chill below the day's low

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

Mount Vernon weather by month

How March compares with the rest of the year at a glance. March is the 8th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan41° / 26°3.392.69.60.0
Feb45° / 30°2.98.42.710.51.1
Mar56° / 38°4.110.81.211.73.7
Apr67° / 49°5.211.30.1135.9
May76° / 59°5.112.90146.3
Jun85° / 68°3.910.4014.65.2
Jul88° / 71°3.410.3014.44.5
Aug86° / 69°2.88.4013.55.2
Sep80° / 61°3.07.3012.37.0
Oct68° / 49°3.67.90116.8
Nov55° / 39°3.88.80.69.93.6
Dec44° / 31°3.28.629.40.9

Cloud cover in March

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in March.

Beyond those clear spells, partly cloudy skies cover about 12% of March, with mostly cloudy or overcast conditions the remaining 59%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24159
34258
44258
54258
64258
74258
84357
94357
104258
114258
124159
134159
144159
154060
164060
174159
184060
194060
204159
214159
224159
234060
244159
254159
264258
274258
284258
294258
304357
314456

Chance of precipitation in March

Any precipitationSnow

Mount Vernon gets around 4.1 in of rain and snow over 10.8 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 34% and peaks near 37% on the wettest days, and about 1 day brings snow. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1317
2317
3317
4317
5316
6316
7316
8325
9325
10325
11335
12334
13344
14344
15344
16354
17353
18353
19363
20363
21373
22373
23372
24372
25372
26372
27372
28372
29371
30371
31371

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 96% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19910
29910
39910
49910
59910
69820
79820
89820
99820
109820
119730
129730
139730
149730
159640
169640
179640
189640
199640
209550
219550
229451
239451
249451
259451
269451
279451
289352
299262
309262
319163

Wind in March

Winds average 8 mph in March.

Across March, daily wind ranges from about 8 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in March

DaylightNight

Daylight runs from about 11 h 06 min 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 72 minutes over March. Sunrise moves from 6:37 AM to 5:51 AM, and sunset from 5:41 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.16:375:41
211.16:355:42
311.16:345:43
411.26:335:44
511.26:315:45
611.36:305:46
711.36:285:47
811.46:275:48
911.46:255:49
1011.46:245:50
1111.56:225:51
1211.56:215:52
1311.66:195:53
1411.66:185:54
1511.66:165:55
1611.76:155:56
1711.76:135:57
1811.86:115:58
1911.86:105:59
2011.96:086:00
2111.96:076:01
2211.96:056:02
2312.06:036:03
2412.06:026:04
2512.16:006:05
2612.15:596:06
2712.25:576:07
2812.25:556:08
2912.25:546:09
3012.35:526:10
3112.35:516:10

Solar energy in March

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in March, about 4.11 kWh/m².

For context, solar energy here swings from a low near 1.9 kWh/m² to a high of 6.46 kWh/m² in June across the year — March's 4.11 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
13.6Moderate
23.7Moderate
33.7Moderate
43.8Moderate
53.8Moderate
63.9Moderate
73.9Moderate
83.9Moderate
94.0Moderate
104.0Moderate
114.0Bright
124.0Bright
134.0Bright
144.1Bright
154.1Bright
164.1Bright
174.1Bright
184.2Bright
194.2Bright
204.2Bright
214.3Bright
224.3Bright
234.3Bright
244.4Bright
254.4Bright
264.5Bright
274.5Bright
284.6Bright
294.6Bright
304.7Bright
314.7Bright
Planning a trip in March

Is March a good time to visit Mount Vernon?

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

3.7
Sightseeing
8th-best month of the year
0.2
Beach & pool
8th-best month of the year

March is a weaker month for outdoor sightseeing in Mount Vernon.

What to pack for Mount Vernon in March

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

In March, Mount Vernon sees daytime highs around 56°F and nights near 38°F. Worth packing: a warm layer and rain gear. About 11 days see rain.

a warm layerrain gear

UV index in Mount Vernon in March

LowModerateHighVery highExtreme

Clear-sky midday UV in March peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mount Vernon peaks around July 10 at about 9 (very high) — 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 highHighModerateJul 10UV 9Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar5High
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Mount Vernon 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 Mount Vernon is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (October, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1417 µg/m³Oct 238 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar12Good
Apr11Good
May14Moderate
Jun16Moderate
Jul18Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Location & terrain

Where is Mount Vernon?

Mount Vernon sits at 38.3°N, 88.9°W, 512 ft above sea level, in United States. The nearest listed city is Marion, 40 mi away.

Topography around Mount Vernon

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

Within 2 miles, the terrain around Mount Vernon has only modest variations in elevation — a maximum elevation change of 174 ft around an average of 489 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 279 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 499 ft.

The land around Mount Vernon is covered by trees (49%) within 2 miles, trees (42%) and cropland (37%) within 10 miles, and cropland (59%) and trees (31%) within 50 miles.

2 miles
174 ft
10 miles
279 ft
50 miles
499 ft
treesgrasslandcroplandartificial surfaceswater
March weather nearby: Marion 40 mi · Carbondale 44 mi · O'Fallon 58 mi · Belleville 60 mi · Fairview Heights 62 mi · Collinsville 63 mi · Edwardsville 66 mi · East Saint Louis 71 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 Mount Vernon (38.3173°, -88.9031°, elevation 512 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).