S
M
T
W
T
F
S
26
72°
59°
27
71°
59°
28
70°
60°
29
72°
61°
30
73°
61°
31
74°
62°
1
75°
60°
2
72°
59°
3
66°
59°
4
71°
60°
5
71°
59°
6
70°
59°
7
71°
58°
8
66°
55°
9
69°
59°
10
69°
58°
11
67°
54°
12
68°
54°
13
67°
53°
14
66°
53°
15
66°
54°
16
67°
58°
17
68°
56°
18
71°
57°
19
70°
57°
20
70°
53°
21
66°
56°
22
70°
57°
23
69°
58°
24
70°
53°
25
68°
54°
26
66°
52°
27
65°
57°
28
65°
57°
29
70°
56°
30
70°
56°
31
69°
55°
1
69°
57°
2
67°
56°
3
69°
54°
4
67°
52°
5
64°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Horncastle
Horncastle's August 2026 forecast shows daily high temperatures ranging from 64° to 75°, with overnight lows between 51° and 62°. The average high for August is 69° with an average low of 57°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Horncastle. See also: September | October | November.