S
M
T
W
T
F
S
27
41°
25°
28
42°
19°
29
41°
21°
30
33°
14°
31
47°
15°
1
32°
18°
2
34°
18°
3
39°
20°
4
44°
27°
5
44°
30°
6
Hist. Avg.
39°
23°
7
Hist. Avg.
39°
23°
8
Hist. Avg.
39°
22°
9
Hist. Avg.
38°
22°
10
Hist. Avg.
38°
22°
11
Hist. Avg.
38°
22°
12
Hist. Avg.
38°
22°
13
Hist. Avg.
38°
22°
14
Hist. Avg.
38°
22°
15
Hist. Avg.
38°
22°
16
Hist. Avg.
38°
22°
17
Hist. Avg.
38°
21°
18
Hist. Avg.
38°
21°
19
Hist. Avg.
38°
21°
20
Hist. Avg.
38°
21°
21
Hist. Avg.
38°
21°
22
Hist. Avg.
38°
21°
23
Hist. Avg.
38°
21°
24
Hist. Avg.
38°
21°
25
Hist. Avg.
38°
21°
26
Hist. Avg.
38°
21°
27
Hist. Avg.
38°
21°
28
Hist. Avg.
38°
21°
29
Hist. Avg.
38°
21°
30
Hist. Avg.
39°
21°
31
Hist. Avg.
39°
21°
1
Hist. Avg.
39°
21°
2
Hist. Avg.
39°
21°
3
Hist. Avg.
39°
21°
4
Hist. Avg.
39°
21°
5
Hist. Avg.
39°
22°
6
Hist. Avg.
40°
22°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
January Weather in Fullerton
Fullerton's January 2027 forecast shows daily high temperatures ranging from 32° to 47°, with overnight lows between 14° and 30°. The average high for January is 40° with an average low of 21°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how January weather will actually feel in Fullerton. See also: February | March | April.
