Paris
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Paris clear sky chart from 2005-11-06 to 2024-01-27.

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
49%
24125
27%
74396
19%
24067
57%
24067
35%
42034

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
36%
949
30%
2458
12%
946
47%
946
38%
1471
January11th to 20thNight
31%
950
28%
2470
9%
950
42%
950
34%
1530
January21st to endNight
31%
1025
30%
2665
10%
1025
43%
1025
33%
1677
February1st to 10thNight
30%
900
24%
2340
8%
900
39%
900
30%
1513
February11th to 20thNight
26%
731
22%
2125
8%
727
36%
727
27%
1342
February21st to endNight
24%
498
28%
1682
10%
498
41%
498
23%
1003
March1st to 10thNight
32%
540
25%
1980
15%
540
45%
540
25%
1163
March11th to 20thNight
32%
540
23%
1980
14%
540
45%
540
23%
1193
March21st to endNight
33%
594
25%
2178
15%
594
48%
594
27%
1236
April1st to 10thNight
30%
540
25%
1980
15%
540
47%
540
29%
1077
April11th to 20thNight
33%
533
26%
1775
17%
533
48%
533
29%
1010
April21st to endNight
35%
540
26%
1766
16%
540
50%
540
34%
970
May1st to 10thNight
42%
540
26%
1620
16%
540
56%
540
32%
952
May11th to 20thNight
49%
531
21%
1594
18%
531
56%
531
34%
931
May21st to endNight
55%
584
24%
1745
19%
582
64%
582
32%
1035
June1st to 10thNight
72%
540
23%
1620
25%
540
75%
540
41%
878
June11th to 20thNight
71%
540
26%
1620
27%
540
74%
540
50%
811
June21st to endNight
79%
540
28%
1620
30%
540
82%
540
50%
818
July1st to 10thNight
77%
525
22%
1575
25%
525
79%
525
39%
873
July11th to 20thNight
85%
522
29%
1566
34%
522
87%
522
56%
731
July21st to endNight
82%
591
28%
1673
33%
558
85%
558
49%
857
August1st to 10thNight
84%
537
32%
1601
36%
534
85%
534
56%
758
August11th to 20thNight
79%
534
33%
1600
37%
534
80%
534
43%
859
August21st to endNight
80%
594
25%
1975
29%
594
80%
594
38%
1049
September1st to 10thNight
76%
540
27%
1940
33%
540
77%
540
39%
961
September11th to 20thNight
71%
540
27%
1980
31%
540
72%
540
31%
1058
September21st to endNight
73%
540
35%
1980
38%
540
77%
540
44%
917
October1st to 10thNight
69%
644
34%
2084
30%
644
73%
644
45%
1024
October11th to 20thNight
53%
720
34%
2160
21%
720
62%
720
42%
1172
October21st to endNight
44%
792
33%
2376
20%
792
54%
792
36%
1348
November1st to 10thNight
51%
740
31%
2220
20%
740
60%
740
40%
1222
November11th to 20thNight
46%
804
31%
2324
17%
804
57%
804
38%
1285
November21st to endNight
37%
950
29%
2470
14%
950
47%
950
33%
1553
December1st to 10thNight
37%
950
30%
2470
13%
950
48%
950
36%
1511
December11th to 20thNight
33%
949
29%
2863
13%
948
41%
948
26%
1803
December21st to endNight
32%
1038
17%
4321
10%
1026
42%
1026
21%
2443

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
13%5%245%3445%7%48%
75088
Night
12%5%2442345%7%54%
74987
TransparencyDay
36%5%10%23%21%6%
74813
Night
31%49%23%23%9%
74782
SeeingDay
14%6%21%28%23%8%
14135
Night
14%6%26%34%18%2
24134

By Month

Percentage Cloud Cover SE (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
15%7%23423345%53%
1707
11th to 20thDay
16%5%2333335%5%52%
1710
21st to endDay
17%6%24323346%49%
1836
February1st to 10thDay
20%8%35%5%23336%41%
1620
11th to 20thDay
20%6%25%5%24446%43%
1735
21st to endDay
25%7%2432333445%
1572
March1st to 10thDay
19%6%25%324436%45%
1980
11th to 20thDay
21%6%34423336%44%
1980
21st to endDay
17%8%35%5%3444444%
2178
April1st to 10thDay
15%5%35%6%2335%6%46%
1980
11th to 20thDay
16%5%24434447%45%
2134
21st to endDay
16%6%245%3445%7%45%
2190
May1st to 10thDay
15%6%26%5%3445%6%44%
2340
11th to 20thDay
13%6%25%5%35%6%6%7%41%
2302
21st to endDay
12%6%36%7%45%5%6%8%38%
2531
June1st to 10thDay
7%426%6%36%7%7%8%44%
2340
11th to 20thDay
6%335%5%46%6%7%8%46%
2340
21st to endDay
5%3244346%7%10%53%
2340
July1st to 10thDay
9%5%26%7%47%6%8%11%35%
2340
11th to 20thDay
3224446%6%7%9%54%
2340
21st to endDay
5%325%6%46%7%6%10%47%
2546
August1st to 10thDay
32135%346%7%9%56%
2328
11th to 20thDay
8%425%6%345%6%9%48%
2301
21st to endDay
6%4345%36%7%6%10%46%
2380
September1st to 10thDay
9%435%5%3445%6%51%
2015
11th to 20thDay
11%5%245%35%6%5%7%47%
1980
21st to endDay
8%42443345%6%58%
1980
October1st to 10thDay
7%424434346%58%
1856
11th to 20thDay
15%5%2332334458%
1800
21st to endDay
17%6%2332243454%
1980
November1st to 10thDay
14%5%14423345%54%
1858
11th to 20thDay
11%423423346%57%
1853
21st to endDay
17%6%24323235%53%
1710
December1st to 10thDay
17%6%24324335%50%
1710
11th to 20thDay
16%9%36%5%23345%44%
2161
21st to endDay
19%8%24433345%45%
3135
January1st to 10thNight
14%6%2422335%7%53%
2458
11th to 20thNight
16%5%24324346%53%
2470
21st to endNight
15%6%2442333453%
2665
February1st to 10thNight
18%7%2442343450%
2340
11th to 20thNight
18%7%35%324345%47%
2125
21st to endNight
19%7%24422345%49%
1682
March1st to 10thNight
17%6%3442335%6%47%
1980
11th to 20thNight
17%6%345%33345%47%
1980
21st to endNight
13%5%25%5%2445%6%49%
2178
April1st to 10thNight
12%42443435%7%52%
1980
11th to 20thNight
15%5%2432445%7%50%
1775
21st to endNight
12%6%24423348%52%
1766
May1st to 10thNight
10%5%35%33445%8%50%
1620
11th to 20thNight
11%4244245%7%9%49%
1593
21st to endNight
8%426%435%5%6%10%47%
1745
June1st to 10thNight
44244335%6%9%57%
1620
11th to 20thNight
431342346%10%60%
1620
21st to endNight
422332346%10%62%
1620
July1st to 10thNight
33245%35%6%6%11%51%
1620
11th to 20thNight
211222346%10%66%
1620
21st to endNight
42135%245%6%10%57%
1772
August1st to 10thNight
321332347%12%61%
1611
11th to 20thNight
5%31343446%11%54%
1600
21st to endNight
3325%5%36%6%6%8%52%
1975
September1st to 10thNight
6%42442345%7%59%
1940
11th to 20thNight
10%425%43346%7%51%
1980
21st to endNight
7%31331335%7%64%
1980
October1st to 10thNight
7%31332345%7%61%
2084
11th to 20thNight
13%41332234462%
2160
21st to endNight
16%6%1331232459%
2376
November1st to 10thNight
11%414323445%59%
2220
11th to 20thNight
10%5%24423445%58%
2324
21st to endNight
17%6%23323445%52%
2470
December1st to 10thNight
15%6%23423446%52%
2470
11th to 20thNight
14%7%345%3434450%
3036
21st to endNight
17%6%24423346%49%
4532

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
35%39%22%26%5%
1708
11th to 20thDay
35%37%25%24%6%
1710
21st to endDay
39%36%19%26%8%
1836
February1st to 10thDay
47%47%18%19%6%
1620
11th to 20thDay
44%47%20%19%6%
1745
21st to endDay
45%35%14%24%9%
1572
March1st to 10thDay
42%37%17%19%11%
1980
11th to 20thDay
42%48%21%19%6%
1980
21st to endDay
44%48%21%18%5%
2178
April1st to 10thDay
40%48%23%17%7%
1980
11th to 20thDay
40%49%21%19%7%
2134
21st to endDay
40%5%8%21%22%3
2190
May1st to 10thDay
41%49%22%19%5%
2340
11th to 20thDay
39%7%14%23%16%1
2306
21st to endDay
43%7%12%22%16%1
2531
June1st to 10thDay
34%7%13%27%16%3
2340
11th to 20thDay
32%7%15%26%17%3
2340
21st to endDay
25%7%13%30%22%3
2340
July1st to 10thDay
38%9%18%23%11%
2276
11th to 20thDay
23%8%14%33%21%2
2271
21st to endDay
29%8%17%33%14%
2405
August1st to 10thDay
23%6%15%34%20%2
2314
11th to 20thDay
32%6%14%27%17%3
2301
21st to endDay
31%8%15%28%15%3
2380
September1st to 10thDay
34%5%9%23%21%8%
2015
11th to 20thDay
34%7%11%20%20%8%
1980
21st to endDay
26%5%9%22%26%12%
1980
October1st to 10thDay
28%411%21%22%14%
1856
11th to 20thDay
31%36%16%29%16%
1800
21st to endDay
35%37%17%26%12%
1980
November1st to 10thDay
33%48%24%23%8%
1858
11th to 20thDay
30%38%22%29%9%
1853
21st to endDay
36%36%18%29%8%
1710
December1st to 10thDay
38%48%24%21%6%
1710
11th to 20thDay
43%35%18%23%8%
2159
21st to endDay
41%45%20%24%6%
3135
January1st to 10thNight
32%37%21%29%8%
2458
11th to 20thNight
35%39%20%25%8%
2470
21st to endNight
37%3417%27%12%
2665
February1st to 10thNight
39%37%20%21%9%
2340
11th to 20thNight
42%27%20%21%8%
2125
21st to endNight
40%36%16%21%13%
1682
March1st to 10thNight
39%47%18%18%14%
1980
11th to 20thNight
41%47%16%22%9%
1980
21st to endNight
36%5%10%21%23%6%
2178
April1st to 10thNight
33%411%21%19%12%
1980
11th to 20thNight
34%48%22%20%12%
1775
21st to endNight
31%411%24%25%4
1766
May1st to 10thNight
33%6%10%22%19%9%
1620
11th to 20thNight
31%6%16%26%17%2
1594
21st to endNight
32%7%15%26%17%4
1746
June1st to 10thNight
24%7%14%31%20%3
1620
11th to 20thNight
19%6%13%35%22%6%
1620
21st to endNight
18%7%12%29%29%5%
1620
July1st to 10thNight
26%8%16%30%19%1
1575
11th to 20thNight
13%7%15%34%26%4
1566
21st to endNight
19%7%17%35%21%2
1673
August1st to 10thNight
16%5%16%33%25%5%
1601
11th to 20thNight
24%6%12%30%22%5%
1600
21st to endNight
27%6%14%30%20%4
1975
September1st to 10thNight
25%5%11%23%27%9%
1940
11th to 20thNight
31%5%11%21%21%11%
1980
21st to endNight
22%49%22%28%16%
1980
October1st to 10thNight
22%411%24%21%17%
2084
11th to 20thNight
27%46%16%27%20%
2160
21st to endNight
32%3420%26%15%
2376
November1st to 10thNight
29%48%20%26%13%
2220
11th to 20thNight
28%38%21%27%13%
2324
21st to endNight
36%37%18%28%8%
2470
December1st to 10thNight
34%310%20%23%10%
2470
11th to 20thNight
40%35%16%25%11%
3037
21st to endNight
37%46%21%25%7%
4532

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
22%11%34%27%6%
270
11th to 20thDay
20%17%35%21%42
270
21st to endDay
22%13%37%20%8%1
282
February1st to 10thDay
26%10%35%23%7%
240
11th to 20thDay
26%15%41%16%3
240
21st to endDay
35%11%38%13%3
198
March1st to 10thDay
23%13%38%21%6%
240
11th to 20thDay
28%16%32%16%7%2
240
21st to endDay
20%15%41%20%4
264
April1st to 10thDay
21%13%35%23%7%
240
11th to 20thDay
25%11%29%25%9%
412
21st to endDay
20%9%36%24%9%2
450
May1st to 10thDay
17%9%32%32%9%1
603
11th to 20thDay
17%5%26%33%15%4
625
21st to endDay
14%6%23%34%18%6%
679
June1st to 10thDay
10%310%37%30%10%
630
11th to 20thDay
7%114%40%29%9%
630
21st to endDay
7%212%32%34%13%
630
July1st to 10thDay
9%27%30%36%17%
621
11th to 20thDay
27%30%45%15%
618
21st to endDay
41330%44%19%
684
August1st to 10thDay
5%5%33%44%13%
626
11th to 20thDay
9%16%31%40%12%
615
21st to endDay
8%1322%40%26%
499
September1st to 10thDay
7%2420%42%26%
305
11th to 20thDay
5%10%23%38%23%
270
21st to endDay
11%39%29%29%19%
270
October1st to 10thDay
5%319%32%33%9%
270
11th to 20thDay
15%5%28%29%19%4
270
21st to endDay
27%7%25%22%17%1
297
November1st to 10thDay
19%431%28%13%5%
270
11th to 20thDay
15%7%37%29%10%3
270
21st to endDay
21%12%30%25%9%3
270
December1st to 10thDay
22%11%30%25%11%1
270
11th to 20thDay
24%9%38%23%5%1
270
21st to endDay
19%13%41%21%5%1
297
January1st to 10thNight
18%10%33%31%7%
950
11th to 20thNight
20%12%35%26%7%
950
21st to endNight
17%8%39%29%6%
1025
February1st to 10thNight
22%11%33%28%5%
900
11th to 20thNight
23%10%37%26%3
731
21st to endNight
23%13%38%23%3
498
March1st to 10thNight
21%9%35%29%6%
540
11th to 20thNight
19%10%35%31%5%
540
21st to endNight
15%10%38%31%5%1
594
April1st to 10thNight
12%11%43%27%7%
540
11th to 20thNight
16%10%37%27%10%
533
21st to endNight
15%6%40%29%9%1
540
May1st to 10thNight
11%6%36%36%9%1
540
11th to 20thNight
13%329%37%17%2
531
21st to endNight
9%324%38%23%3
584
June1st to 10thNight
6%311%44%34%3
540
11th to 20thNight
6%118%51%23%1
540
21st to endNight
4111%39%40%5%
540
July1st to 10thNight
418%39%44%5%
525
11th to 20thNight
415%35%49%6%
522
21st to endNight
315%36%47%8%
591
August1st to 10thNight
415%42%42%6%
537
11th to 20thNight
7%15%39%42%6%
534
21st to endNight
6%1239%44%7%
594
September1st to 10thNight
7%16%34%45%6%
540
11th to 20thNight
13%16%36%40%4
540
21st to endNight
8%111%42%34%4
540
October1st to 10thNight
9%115%43%29%3
644
11th to 20thNight
14%424%38%17%2
720
21st to endNight
20%5%29%29%15%2
792
November1st to 10thNight
12%329%39%15%1
740
11th to 20thNight
12%8%30%39%10%1
804
21st to endNight
21%8%31%29%11%
950
December1st to 10thNight
18%8%33%34%7%
950
11th to 20thNight
22%8%32%32%6%
950
21st to endNight
20%10%33%30%8%
1045
Page generated at 2024-01-24 08:37:31. Version ac07

Copyright 2024 Attilla Danko


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