Central Valley Region
Costa Rica's Central Valley is the urban population center for good reason, with daily average temperatures between 72 and 75 degrees, the Central Valley has the mildest climate in the whole country.
read more closeThe Central Valley weather region includes parts of the provinces of Heredia, San Jose, Alajuela and Cartago, including popular cities like San Jose, Heredia, Escazu, Santa Ana, Cartago, Barva and Grecia, among many others.
Max average temperatures rarely exceed 84 degrees while the lowest average temperatures are a mere 64 degrees. Relative humidity averages about 75 percent, dropping to 69 percent during the dry season.
The dry season runs from December to March, with April and November being months of transition. During the dry season, the humidity is lower. The months of January through March are also marked with persistent northeast winds and lots of sunshine.
The wet season months of May through November are characterized by less sun and more rain. July tends to be the driest of the wet months and is considered a miniature dry season. Usually, you get at least four hours of sun in the morning before the afternoon storms develop. September and October are the rainiest months (averaging 26 inches per month) of the year, and the most humid. The Central Valley weather region receives 77.4 inches of annual rainfall.
As you ascend into the mountains north of Heredia, especially up past Barva, the weather tends to be cooler and cloudier.
Alajuela
| Month |
Average Highs |
Average Lows |
Average Rainfall |
Humidity |
|||
|---|---|---|---|---|---|---|---|
|
|
F |
C |
F |
C |
in. |
mm |
% |
| Jan. |
81 |
27 |
62 |
17 |
0.28 |
7 |
69 |
| Feb. |
83 |
28 |
62 |
17 |
0.47 |
12 |
69 |
| Mar. |
85 |
29 |
63 |
17 |
0.55 |
14 |
67 |
| Apr. |
85 |
29 |
63 |
17 |
3.23 |
82 |
70 |
| May |
82 |
28 |
64 |
18 |
10.67 |
271 |
82 |
| Jun. |
81 |
27 |
64 |
18 |
10.63 |
270 |
82 |
| Jul. |
81 |
27 |
64 |
18 |
7.09 |
180 |
84 |
| Aug. |
81 |
27 |
63 |
17 |
10.16 |
258 |
79 |
| Sep. |
80 |
27 |
63 |
17 |
13.7 |
348 |
82 |
| Oct. |
80 |
27 |
63 |
17 |
13.39 |
340 |
87 |
| Nov. |
80 |
27 |
63 |
17 |
19.57 |
497 |
86 |
| Dec. |
81 |
27 |
63 |
17 |
20.87 |
530 |
80 |
Cartago
| Month |
Average Highs |
Average Lows |
Average Rainfall |
Humidity |
|||
|---|---|---|---|---|---|---|---|
|
|
F |
C |
F |
C |
in. |
mm |
% |
| Jan. |
73 |
23 |
55 |
13 |
1.2 |
31 |
78 |
| Feb. |
74 |
23 |
54 |
12 |
0.73 |
19 |
79 |
| Mar. |
77 |
25 |
55 |
13 |
0.6 |
16 |
77 |
| Apr. |
78 |
26 |
56 |
13 |
1.85 |
48 |
79 |
| May |
79 |
26 |
58 |
14 |
7.27 |
187 |
83 |
| Jun. |
77 |
25 |
57 |
14 |
7.87 |
202 |
83 |
| Jul. |
77 |
25 |
58 |
14 |
5.06 |
130 |
83 |
| Aug. |
77 |
25 |
57 |
14 |
6.06 |
156 |
84 |
| Sep. |
77 |
25 |
56 |
14 |
9.71 |
249 |
84 |
| Oct. |
78 |
25 |
57 |
14 |
9.78 |
251 |
85 |
| Nov. |
75 |
24 |
57 |
14 |
4.31 |
110 |
84 |
| Dec. |
73 |
23 |
56 |
14 |
2.28 |
58 |
8 |
Grecia
| Month |
Average Highs |
Average Lows |
Average Rainfall |
Humidity |
|||
|---|---|---|---|---|---|---|---|
|
|
F |
C |
F |
C |
in. |
mm |
% |
| Jan. |
84 |
29 |
63 |
17 |
0.29 |
7 |
70 |
| Feb. |
86 |
30 |
64 |
18 |
0.48 |
12 |
69 |
| Mar. |
87 |
31 |
65 |
18 |
0.58 |
15 |
68 |
| Apr. |
87 |
31 |
65 |
18 |
2.7 |
69 |
71 |
| May |
84 |
29 |
65 |
19 |
10.07 |
258 |
83 |
| Jun. |
82 |
28 |
65 |
18 |
10.83 |
278 |
87 |
| Jul. |
82 |
28 |
65 |
18 |
7.56 |
194 |
83 |
| Aug. |
82 |
28 |
64 |
18 |
10.49 |
269 |
85 |
| Sep. |
81 |
27 |
64 |
18 |
13.12 |
336 |
89 |
| Oct. |
81 |
27 |
64 |
18 |
12.79 |
328 |
89 |
| Nov. |
82 |
28 |
64 |
18 |
5.69 |
146 |
84 |
| Dec. |
83 |
28 |
64 |
18 |
1.23 |
32 |
74 |
Heredia
| Month |
Average Highs |
Average Lows |
Average Rainfall |
Humidity |
|||
|---|---|---|---|---|---|---|---|
|
|
F |
C |
F |
C |
in. |
mm |
% |
| Jan. |
76 |
24 |
59 |
15 |
0.78 |
20 |
73 |
| Feb. |
75 |
24 |
57 |
14 |
0.96 |
25 |
72 |
| Mar. |
79 |
26 |
58 |
15 |
1.91 |
49 |
71 |
| Apr. |
79 |
26 |
59 |
15 |
4.86 |
125 |
74 |
| May |
78 |
26 |
61 |
16 |
12.49 |
320 |
83 |
| Jun. |
76 |
25 |
59 |
15 |
12.88 |
330 |
85 |
| Jul. |
76 |
25 |
60 |
16 |
8.03 |
205 |
82 |
| Aug. |
76 |
25 |
60 |
16 |
9.73 |
249 |
84 |
| Sep. |
76 |
24 |
59 |
15 |
15.55 |
399 |
87 |
| Oct. |
76 |
25 |
59 |
15 |
16.42 |
421 |
87 |
| Nov. |
75 |
24 |
60 |
15 |
7.02 |
180 |
82 |
| Dec. |
75 |
24 |
60 |
16 |
2.14 |
55 |
76 |
Irazu Volcano
| Month |
Average Highs |
Average Lows |
Average Rainfall |
Humidity |
|||
|---|---|---|---|---|---|---|---|
|
|
F |
C |
F |
C |
in. |
mm |
% |
| Jan. |
52 |
11 |
39 |
4 |
1.34 |
34 |
80 |
| Feb. |
52 |
11 |
39 |
4 |
2.36 |
60 |
76 |
| Mar. |
64 |
18 |
40 |
4 |
1.1 |
28 |
74 |
| Apr. |
54 |
12 |
40 |
4 |
3.86 |
98 |
81 |
| May |
53 |
12 |
41 |
5 |
8.27 |
210 |
87 |
| Jun. |
51 |
11 |
42 |
6 |
8.9 |
226 |
91 |
| Jul. |
50 |
10 |
41 |
5 |
6.77 |
172 |
90 |
| Aug. |
51 |
11 |
39 |
4 |
8.27 |
210 |
90 |
| Sep. |
51 |
11 |
41 |
5 |
8.94 |
227 |
90 |
| Oct. |
51 |
11 |
41 |
5 |
10.63 |
270 |
90 |
| Nov. |
61 |
16 |
41 |
5 |
11.42 |
290 |
89 |
| Dec. |
51 |
11 |
39 |
4 |
6.38 |
162 |
83 |
Poas Volcano
| Month |
Average Highs |
Average Lows |
Average Rainfall |
Humidity |
|||
|---|---|---|---|---|---|---|---|
|
|
F |
C |
F |
C |
in. |
mm |
% |
| Jan. |
69 |
21 |
53 |
12 |
5.91 |
150 |
82 |
| Feb. |
89 |
32 |
53 |
12 |
3.82 |
97 |
81 |
| Mar. |
71 |
22 |
53 |
12 |
1.65 |
42 |
82 |
| Apr. |
71 |
22 |
55 |
13 |
4.8 |
122 |
83 |
| May |
71 |
22 |
57 |
14 |
13.7 |
348 |
90 |
| Jun. |
71 |
22 |
57 |
14 |
16.54 |
420 |
91 |
| Jul. |
69 |
21 |
57 |
14 |
14.13 |
359 |
89 |
| Aug. |
69 |
21 |
57 |
14 |
18.03 |
458 |
89 |
| Sep. |
71 |
22 |
55 |
13 |
19.41 |
493 |
91 |
| Oct. |
59 |
15 |
57 |
14 |
16.77 |
426 |
91 |
| Nov. |
58 |
14 |
57 |
14 |
16.89 |
429 |
89 |
| Dec. |
59 |
15 |
57 |
14 |
12.99 |
330 |
85 |
San Jose
| Month |
Average Highs |
Average Lows |
Average Rainfall |
Humidity |
|||
|---|---|---|---|---|---|---|---|
|
|
F |
C |
F |
C |
in. |
mm |
% |
| Jan. |
73 |
23 |
59 |
15 |
0.39 |
10 |
82 |
| Feb. |
75 |
24 |
59 |
15 |
0.24 |
6 |
80 |
| Mar. |
77 |
25 |
60 |
16 |
0.47 |
12 |
78 |
| Apr. |
78 |
26 |
60 |
16 |
1.73 |
44 |
79 |
| May |
78 |
26 |
62 |
17 |
8.86 |
225 |
84 |
| Jun. |
78 |
26 |
62 |
17 |
11.3 |
287 |
85 |
| Jul. |
77 |
25 |
62 |
17 |
8.46 |
215 |
84 |
| Aug. |
77 |
25 |
62 |
17 |
9.8 |
249 |
85 |
| Sep. |
76 |
24 |
60 |
16 |
13.07 |
332 |
86 |
| Oct. |
77 |
25 |
60 |
16 |
13.07 |
332 |
86 |
| Nov. |
75 |
24 |
60 |
16 |
5.59 |
142 |
84 |
| Dec. |
73 |
23 |
59 |
15 |
1.61 |
41 |
83 |
Source: National Weather Services of Costa Rica
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