Tijuana
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Tijuana clear sky chart from 2005-11-06 to 2024-01-13.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
69%
25019
19%
74526
17%
24967
70%
24967
20%
53199

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 10thNight
64%
757
20%
2457
20%
756
68%
756
19%
1692
January11th to 20thNight
71%
728
24%
2240
23%
728
74%
728
20%
1582
January21st to endNight
66%
792
24%
2376
20%
792
71%
792
20%
1682
February1st to 10thNight
70%
720
21%
2160
21%
720
73%
720
20%
1522
February11th to 20thNight
61%
700
19%
2098
19%
700
64%
700
18%
1537
February21st to endNight
62%
592
19%
1776
19%
592
66%
592
19%
1290
March1st to 10thNight
61%
720
15%
2160
16%
720
64%
720
17%
1606
March11th to 20thNight
65%
720
18%
2070
19%
720
66%
720
18%
1526
March21st to endNight
65%
792
16%
2066
13%
792
67%
792
20%
1551
April1st to 10thNight
63%
720
17%
1800
13%
720
64%
720
22%
1353
April11th to 20thNight
61%
711
17%
1779
12%
711
62%
711
20%
1372
April21st to endNight
61%
720
16%
1800
10%
720
61%
720
21%
1377
May1st to 10thNight
61%
626
15%
1706
10%
626
61%
626
19%
1284
May11th to 20thNight
59%
531
15%
1595
12%
531
60%
531
18%
1206
May21st to endNight
58%
582
18%
1746
14%
582
58%
582
19%
1294
June1st to 10thNight
60%
540
13%
1620
11%
540
60%
540
17%
1252
June11th to 20thNight
69%
540
17%
1620
14%
540
69%
540
21%
1165
June21st to endNight
71%
540
18%
1620
15%
540
71%
540
23%
1133
July1st to 10thNight
74%
525
15%
1575
13%
525
74%
525
24%
1094
July11th to 20thNight
77%
522
19%
1566
16%
522
77%
522
23%
1083
July21st to endNight
73%
726
14%
1802
10%
686
73%
686
20%
1358
August1st to 10thNight
78%
716
19%
1780
12%
712
78%
712
30%
1218
August11th to 20thNight
73%
712
21%
1780
13%
712
73%
712
27%
1268
August21st to endNight
78%
792
22%
1980
17%
792
78%
792
28%
1393
September1st to 10thNight
76%
720
24%
1822
19%
720
77%
720
28%
1279
September11th to 20thNight
79%
720
24%
1980
24%
720
80%
720
26%
1351
September21st to endNight
77%
720
23%
1980
24%
720
77%
720
26%
1353
October1st to 10thNight
75%
720
18%
1980
17%
720
76%
720
22%
1424
October11th to 20thNight
72%
720
26%
1980
25%
720
74%
720
26%
1361
October21st to endNight
74%
792
22%
2428
23%
792
76%
792
22%
1640
November1st to 10thNight
74%
740
16%
2405
18%
740
75%
740
18%
1701
November11th to 20thNight
76%
760
26%
2470
29%
760
79%
760
24%
1595
November21st to endNight
70%
760
20%
2470
22%
760
72%
760
19%
1705
December1st to 10thNight
67%
760
19%
2470
20%
760
68%
760
17%
1737
December11th to 20thNight
62%
760
19%
2948
19%
759
65%
759
12%
2160
December21st to endNight
63%
823
11%
4421
19%
817
66%
817
10%
3055

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
5%42432345%7%60%
74835
Night
7%8%35%42445%7%52%
74933
TransparencyDay
15%36%5%12%17%15%
74570
Night
20%36%411%13%15%
74720
SeeingDay
7%5%21%38%23%6%
14609
Night
9%39%34%36%10%
25041

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
10%4143245%48%56%
1708
11th to 20thDay
7%5%243245%48%57%
1760
21st to endDay
9%5%24423336%58%
1980
February1st to 10thDay
7%324434446%60%
1800
11th to 20thDay
8%5%2433345%8%53%
1750
21st to endDay
10%425%5%36%5%6%6%49%
1480
March1st to 10thDay
9%5%35%43446%10%49%
1800
11th to 20thDay
9%32443446%9%53%
1887
21st to endDay
5%42442445%8%58%
2286
April1st to 10thDay
7%435%5%2445%7%55%
2160
11th to 20thDay
5%42332345%7%62%
2129
21st to endDay
7%414312349%62%
2160
May1st to 10thDay
8%6%2433345%8%56%
2251
11th to 20thDay
5%7%24324347%60%
2301
21st to endDay
6%7%24423448%58%
2530
June1st to 10thDay
47%2441235%8%58%
2340
11th to 20thDay
3423323337%67%
2340
21st to endDay
36%34213346%64%
2340
July1st to 10thDay
36%25%424447%59%
2340
11th to 20thDay
142442346%10%60%
2340
21st to endDay
341432447%9%58%
2406
August1st to 10thDay
1424223437%67%
2149
11th to 20thDay
2323223346%71%
2122
21st to endDay
231332345%8%66%
2376
September1st to 10thDay
341232445%7%65%
2138
11th to 20thDay
2313313346%71%
1980
21st to endDay
3312222346%72%
1980
October1st to 10thDay
4323423448%64%
1980
11th to 20thDay
6%414322446%66%
1980
21st to endDay
3313312345%72%
1923
November1st to 10thDay
4314323348%64%
1674
11th to 20thDay
5%313323446%65%
1710
21st to endDay
6%41333345%8%59%
1710
December1st to 10thDay
7%4244335%6%8%55%
1710
11th to 20thDay
11%6%25%4345%5%8%47%
2169
21st to endDay
11%5%35%5%45%6%7%8%42%
3146
January1st to 10thNight
10%5%23324347%56%
2457
11th to 20thNight
7%5%23434447%56%
2240
21st to endNight
12%42432335%6%57%
2376
February1st to 10thNight
8%5%25%423346%59%
2160
11th to 20thNight
10%7%25%424445%52%
2098
21st to endNight
11%5%245%25%5%5%6%50%
1776
March1st to 10thNight
11%7%35%42445%8%47%
2160
11th to 20thNight
11%7%3433447%8%47%
2070
21st to endNight
8%7%245%35%5%6%7%49%
2066
April1st to 10thNight
10%8%45%42345%8%47%
1800
11th to 20thNight
10%10%35%323347%50%
1779
21st to endNight
9%10%35%6%3335%6%47%
1800
May1st to 10thNight
9%12%45%43445%8%42%
1706
11th to 20thNight
6%16%7%6%43445%7%38%
1594
21st to endNight
11%15%35%424447%40%
1746
June1st to 10thNight
7%18%5%7%5%3446%8%35%
1620
11th to 20thNight
5%13%46%3245%49%45%
1620
21st to endNight
312%5%6%42446%7%47%
1620
July1st to 10thNight
312%47%33447%9%44%
1620
11th to 20thNight
210%47%5%4347%8%47%
1620
21st to endNight
411%45%5%3445%11%45%
1908
August1st to 10thNight
29%35%31446%9%54%
1790
11th to 20thNight
49%46%5%2345%10%50%
1780
21st to endNight
38%24322348%60%
1980
September1st to 10thNight
47%36%424347%57%
1822
11th to 20thNight
5%6%23223446%62%
1980
21st to endNight
47%23313337%63%
1980
October1st to 10thNight
5%6%24324347%59%
1980
11th to 20thNight
8%5%24323346%60%
1980
21st to endNight
6%6%23323345%63%
2428
November1st to 10thNight
6%5%35%312346%62%
2405
11th to 20thNight
45%23423346%65%
2470
21st to endNight
6%5%34425%45%7%55%
2470
December1st to 10thNight
9%6%2433445%6%53%
2470
11th to 20thNight
11%8%35%5%335%5%7%45%
3041
21st to endNight
10%6%36%6%45%5%6%7%42%
4521

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
17%39%410%15%15%
1709
11th to 20thDay
15%41%37%14%21%
1760
21st to endDay
20%37%5%9%11%18%
1980
February1st to 10thDay
18%35%311%13%21%
1800
11th to 20thDay
23%36%5%10%15%12%
1760
21st to endDay
23%37%39%14%14%
1480
March1st to 10thDay
20%37%5%13%12%13%
1800
11th to 20thDay
20%36%6%12%16%10%
1887
21st to endDay
18%37%5%17%14%10%
2286
April1st to 10thDay
19%35%6%14%18%7%
2160
11th to 20thDay
17%35%7%14%16%12%
2132
21st to endDay
14%35%419%20%9%
2160
May1st to 10thDay
12%35%6%16%18%12%
2251
11th to 20thDay
12%36%5%17%21%9%
2304
21st to endDay
12%36%6%14%26%6%
2530
June1st to 10thDay
16%36%6%17%16%10%
2340
11th to 20thDay
11%35%311%18%22%
2340
21st to endDay
11%35%26%18%28%
2340
July1st to 10thDay
11%36%38%20%22%
2276
11th to 20thDay
9%37%7%18%18%11%
2271
21st to endDay
14%38%9%17%13%8%
2272
August1st to 10thDay
10%35%414%20%18%
2135
11th to 20thDay
11%34%415%22%14%
2122
21st to endDay
11%36%212%21%18%
2376
September1st to 10thDay
12%36%37%21%21%
2138
11th to 20thDay
7%35%29%22%24%
1980
21st to endDay
8%35%411%20%22%
1980
October1st to 10thDay
15%36%5%13%16%16%
1980
11th to 20thDay
13%35%210%18%23%
1980
21st to endDay
9%37%310%16%26%
1923
November1st to 10thDay
14%40%415%11%16%
1674
11th to 20thDay
11%38%39%13%26%
1710
21st to endDay
13%40%49%14%20%
1710
December1st to 10thDay
15%38%410%14%18%
1710
11th to 20thDay
28%33%8%10%10%11%
2168
21st to endDay
31%28%7%17%12%6%
3146
January1st to 10thNight
15%40%49%14%18%
2457
11th to 20thNight
15%41%16%14%22%
2240
21st to endNight
20%36%6%9%8%20%
2376
February1st to 10thNight
21%35%39%13%20%
2160
11th to 20thNight
23%37%310%13%14%
2099
21st to endNight
22%37%48%14%15%
1776
March1st to 10thNight
25%37%5%10%9%14%
2160
11th to 20thNight
24%36%6%12%12%11%
2070
21st to endNight
22%37%5%14%11%10%
2066
April1st to 10thNight
23%35%5%15%13%9%
1800
11th to 20thNight
25%36%412%11%11%
1779
21st to endNight
24%36%412%14%10%
1800
May1st to 10thNight
25%36%6%11%12%11%
1706
11th to 20thNight
25%36%5%15%10%8%
1595
21st to endNight
23%36%315%16%7%
1746
June1st to 10thNight
29%35%6%12%12%5%
1620
11th to 20thNight
22%35%39%17%15%
1620
21st to endNight
19%35%28%13%24%
1620
July1st to 10thNight
16%37%38%20%17%
1575
11th to 20thNight
16%37%5%15%19%9%
1566
21st to endNight
23%37%9%15%12%5%
1802
August1st to 10thNight
13%34%415%19%14%
1780
11th to 20thNight
17%34%317%17%11%
1780
21st to endNight
14%36%39%21%17%
1980
September1st to 10thNight
14%37%28%16%23%
1822
11th to 20thNight
14%36%26%17%25%
1980
21st to endNight
16%35%28%22%18%
1980
October1st to 10thNight
19%37%410%13%16%
1980
11th to 20thNight
16%35%310%13%23%
1980
21st to endNight
15%37%27%14%25%
2428
November1st to 10thNight
17%41%413%10%16%
2405
11th to 20thNight
11%38%39%12%27%
2470
21st to endNight
17%39%311%12%19%
2470
December1st to 10thNight
18%40%48%11%20%
2470
11th to 20thNight
28%34%5%10%13%10%
3041
21st to endNight
30%30%9%15%8%7%
4521

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
17%319%36%22%2
270
11th to 20thDay
12%5%23%38%20%3
368
21st to endDay
9%9%31%35%13%3
462
February1st to 10thDay
10%6%28%34%18%4
420
11th to 20thDay
8%12%33%35%12%1
415
21st to endDay
11%11%36%31%10%1
346
March1st to 10thDay
12%10%36%30%11%1
420
11th to 20thDay
11%9%32%32%13%3
420
21st to endDay
6%15%36%32%8%2
462
April1st to 10thDay
9%8%35%30%15%4
420
11th to 20thDay
6%10%34%38%8%3
412
21st to endDay
5%10%30%36%14%5%
420
May1st to 10thDay
11%9%27%34%15%4
423
11th to 20thDay
10%8%25%39%16%2
448
21st to endDay
9%9%28%36%16%3
485
June1st to 10thDay
3321%40%28%4
450
11th to 20thDay
3217%44%28%6%
450
21st to endDay
5%112%46%28%9%
450
July1st to 10thDay
48%39%38%11%
446
11th to 20thDay
25%39%40%15%
444
21st to endDay
21339%41%14%
487
August1st to 10thDay
28%43%34%13%
447
11th to 20thDay
315%42%36%14%
437
21st to endDay
3444%37%11%
495
September1st to 10thDay
6%111%47%28%7%
450
11th to 20thDay
4218%47%26%4
450
21st to endDay
4219%42%26%7%
450
October1st to 10thDay
36%23%42%24%3
450
11th to 20thDay
5%5%26%41%20%3
450
21st to endDay
4323%38%25%7%
415
November1st to 10thDay
6%6%17%40%27%6%
270
11th to 20thDay
4419%39%29%6%
270
21st to endDay
7%7%23%37%19%7%
270
December1st to 10thDay
9%420%44%20%4
270
11th to 20thDay
6%220%41%25%5%
270
21st to endDay
16%8%22%33%17%4
297
January1st to 10thNight
11%415%38%23%9%
760
11th to 20thNight
8%410%43%27%8%
728
21st to endNight
12%312%43%25%5%
792
February1st to 10thNight
9%210%40%30%8%
720
11th to 20thNight
11%414%41%24%6%
704
21st to endNight
11%415%42%25%3
592
March1st to 10thNight
13%413%42%24%3
720
11th to 20thNight
13%39%40%28%7%
720
21st to endNight
9%413%41%29%5%
792
April1st to 10thNight
12%310%41%29%5%
720
11th to 20thNight
9%5%14%39%26%6%
711
21st to endNight
9%6%10%37%31%7%
720
May1st to 10thNight
9%312%36%33%8%
626
11th to 20thNight
10%411%35%33%7%
531
21st to endNight
13%312%36%30%5%
584
June1st to 10thNight
10%39%43%29%6%
540
11th to 20thNight
8%27%31%46%5%
540
21st to endNight
5%6%29%53%7%
540
July1st to 10thNight
6%324%53%14%
525
11th to 20thNight
4217%62%16%
522
21st to endNight
6%215%55%21%
726
August1st to 10thNight
41218%53%22%
716
11th to 20thNight
6%1210%56%26%
712
21st to endNight
5%1213%54%25%
792
September1st to 10thNight
6%1419%55%16%
720
11th to 20thNight
6%15%22%53%13%
720
21st to endNight
6%2428%44%15%
720
October1st to 10thNight
9%15%38%41%6%
720
11th to 20thNight
10%27%36%36%10%
720
21st to endNight
8%38%34%32%15%
792
November1st to 10thNight
6%27%39%34%11%
740
11th to 20thNight
5%26%42%35%11%
760
21st to endNight
8%212%39%31%9%
760
December1st to 10thNight
11%211%43%25%7%
760
11th to 20thNight
14%411%42%22%7%
760
21st to endNight
10%415%38%25%7%
836
Page generated at 2024-01-09 22:25:02. Version ac07

Copyright 2024 Attilla Danko


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