S
M
T
W
T
F
S
29
76°
46°
30
76°
46°
31
57°
40°
1
56°
37°
2
74°
38°
3
56°
34°
4
64°
36°
5
71°
39°
6
76°
37°
7
72°
44°
8
81°
47°
9
71°
33°
10
63°
34°
11
57°
34°
12
66°
38°
13
73°
42°
14
62°
30°
15
66°
37°
16
67°
36°
17
67°
38°
18
68°
38°
19
69°
39°
20
69°
39°
21
68°
38°
22
69°
39°
23
68°
37°
24
60°
33°
25
57°
31°
26
63°
33°
27
66°
36°
28
65°
33°
29
59°
33°
30
69°
39°
1
69°
41°
2
71°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
April Weather in Sullivan
Sullivan's April 2026 forecast shows daily high temperatures ranging from 56° to 81°, with overnight lows between 30° and 47°. The average high for April is 67° with an average low of 37°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how April weather will actually feel in Sullivan. See also: May | June | July.