Hannibal weather in August

In August, Hannibal sees average daytime highs of 85°F and overnight lows near 66°F, with 3.2 in of rain across 9.2 wet days and about 13.6 hours of daylight. It is the 2nd-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 85°F through the month. The sky is clear or mostly clear about 41% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 h 06 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Hannibal's 2nd-clearest and 12th-windiest month. For the whole year in context, see Hannibal's year-round climate.

Daytime high
85°
2nd warmest
Overnight low
66°
11th coldest
Rainfall
3.2 in
9.2 wet days
Daylight
13 h 36 min
5:22 AM – 6:57 PM
Cloud cover
50%
2nd clearest
Wind
6 mph
12th windiest
Solar energy
5.74 kWh/m²
Travel score
5.6
out of 10

Hannibal is city in Marion and Ralls counties in Missouri, United States.

Density
425/km²
people per km²
Founded
1819

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 85°F through the month.

A typical August day in Hannibal reaches about 85°F in the afternoon and slips back to 66°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 77°F and 93°F. Set against its neighbours, August runs about 2°F cooler than July and about 7°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18568
28568
38568
48568
58567
68567
78567
88567
98567
108567
118567
128567
138567
148567
158566
168466
178466
188466
198466
208466
218466
228466
238466
248466
258466
268465
278465
288465
298365
308365
318364

How August really feels in Hannibal

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

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Hannibal weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan36° / 21°2.07.249.50.0
Feb41° / 24°2.37.23.210.40.3
Mar53° / 34°3.110.11.811.72.9
Apr64° / 45°4.511.60.3135.4
May74° / 56°4.713.2014.26.3
Jun83° / 65°4.210.4014.85.8
Jul86° / 69°3.59.4014.55.1
Aug85° / 66°3.29.2013.65.6
Sep78° / 58°3.37.6012.37.2
Oct65° / 46°2.98.90.110.96.2
Nov52° / 35°3.17.91.19.82.9
Dec40° / 26°2.27.32.79.20.2

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 40%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16238
26238
36139
46139
56139
66139
76139
86139
96040
106040
116040
126040
136040
146040
156040
166040
176040
186040
195941
205941
216040
226040
235941
245941
256040
266040
276040
286139
296238
306238
316238

Chance of precipitation in August

Any precipitation

Hannibal gets around 3.2 in of rain over 9.2 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 30% and peaks near 31% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
129
229
329
429
529
629
729
829
930
1030
1130
1231
1331
1431
1531
1631
1731
1831
1931
2031
2131
2231
2330
2430
2529
2628
2728
2827
2927
3027
3126

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the muggy band about 31% of days. Sticky, muggy-or-worse air turns up on roughly 52% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
15152529251
25152529251
35152530241
45152530241
55152530231
65152530231
76152530231
86152530221
96162531221
107162530221
117162531211
127162531210
137162531210
147162531200
158162431200
168162431200
178162431200
188162431200
198162431200
208162432200
218162432200
228162432200
238162332200
248162332200
258162432190
269162432190
2710172432180
2810172431170
2911172431170
3012182430160
3113182430150

Wind in August

Winds average 6 mph in August, the calmest month.

Across August, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 06 min at the start of August to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 5:08 AM to 5:37 AM, and sunset from 7:15 PM to 6:34 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.15:087:15
214.15:097:14
314.15:107:13
414.05:117:12
514.05:127:11
613.95:137:10
713.95:147:08
813.95:157:07
913.85:167:06
1013.85:167:05
1113.85:177:03
1213.75:187:02
1313.75:197:01
1413.75:207:00
1513.65:216:58
1613.65:226:57
1713.55:236:55
1813.55:246:54
1913.55:256:53
2013.45:266:51
2113.45:276:50
2213.35:286:48
2313.35:296:47
2413.35:306:45
2513.25:316:44
2613.25:326:42
2713.15:336:41
2813.15:346:39
2913.05:356:37
3013.05:366:36
3113.05:376:34

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.74 kWh/m².

For context, solar energy here swings from a low near 1.86 kWh/m² to a high of 6.45 kWh/m² in June across the year — August's 5.74 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.2Intense
26.1Intense
36.1Intense
46.1Intense
56.1Intense
66.0Intense
76.0Intense
86.0Bright
96.0Bright
105.9Bright
115.9Bright
125.8Bright
135.8Bright
145.8Bright
155.8Bright
165.7Bright
175.7Bright
185.7Bright
195.6Bright
205.6Bright
215.6Bright
225.6Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.4Bright
285.4Bright
295.4Bright
305.3Bright
315.3Bright
Planning a trip in August

Hazard calendar for Hannibal

In seasonPeak

In August, Hannibal sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Hannibal sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is August a good time to visit Hannibal?

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

5.6
Sightseeing
5th-best month of the year
7.3
Beach & pool
1st-best month of the year

August is a reasonable time to visit Hannibal for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Hannibal in August

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

In August, Hannibal sees daytime highs around 85°F and nights near 66°F. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Hannibal in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Hannibal peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 21UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Hannibal in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual average.

Air quality in Hannibal is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (October, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodJul 1716 µg/m³Oct 237 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Moderate
Mar12Good
Apr10Good
May13Moderate
Jun14Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct7Good
Nov7Good
Dec8Good
Location & terrain

Where is Hannibal?

Hannibal sits at 39.7°N, 91.4°W, 502 ft above sea level, in United States. The nearest listed city is Quincy, 16 mi away.

Topography around Hannibal

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

Within 2 miles, the terrain around Hannibal has only modest variations in elevation — a maximum elevation change of 305 ft around an average of 558 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 430 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 702 ft.

The land around Hannibal is covered by trees (49%) within 2 miles, cropland (46%) and trees (32%) within 10 miles, and cropland (53%) and trees (32%) within 50 miles.

2 miles
305 ft
10 miles
430 ft
50 miles
702 ft
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Quincy 16 mi · Jacksonville 60 mi · Macomb 63 mi · Wentzville 68 mi · O'Fallon 71 mi · Kirksville 73 mi · Columbia 74 mi · Saint Peters 74 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 Hannibal (39.7084°, -91.3585°, elevation 502 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).