Caresland
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Caresland clear sky chart from 2005-11-05 to 2017-09-16.

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
43%
15204
13%
46772
9%
15178
47%
15178
22%
31704

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 15thNight
33%
895
11%
2685
7%
895
36%
895
15%
2012
January16th to endNight
37%
828
17%
2748
12%
828
44%
828
19%
1844
February1st to 15thNight
43%
698
13%
2395
12%
696
48%
696
18%
1608
February16th to endNight
41%
632
14%
1989
12%
632
46%
632
18%
1414
March1st to 15thNight
34%
720
13%
2105
8%
720
40%
720
18%
1517
March16th to endNight
34%
768
10%
2106
3%
768
39%
768
17%
1592
April1st to 15thNight
35%
617
11%
1697
5%
617
38%
617
18%
1257
April16th to endNight
39%
540
14%
1620
10%
540
44%
540
21%
1120
May1st to 15thNight
46%
443
12%
1428
11%
443
49%
443
23%
920
May16th to endNight
44%
374
5%
1309
3%
374
45%
374
16%
921
June1st to 15thNight
46%
360
1%
1260
0%
360
46%
360
16%
910
June16th to endNight
54%
360
1%
1260
0%
360
54%
360
23%
794
July1st to 15thNight
63%
340
2%
1190
0%
340
63%
340
27%
688
July16th to endNight
62%
376
11%
1269
11%
354
66%
354
31%
691
August1st to 15thNight
64%
418
12%
1490
14%
416
66%
416
26%
879
August16th to endNight
62%
573
22%
1719
19%
573
65%
573
38%
957
September1st to 15thNight
56%
648
17%
1809
13%
648
58%
648
34%
1116
September16th to endNight
53%
656
19%
1816
13%
656
58%
656
37%
1081
October1st to 15thNight
45%
660
18%
1936
10%
660
51%
660
22%
1322
October16th to endNight
46%
704
19%
2288
13%
704
55%
704
25%
1449
November1st to 15thNight
36%
834
18%
2409
10%
834
43%
834
23%
1646
November16th to endNight
33%
900
14%
2664
8%
900
39%
900
21%
1848
December1st to 15thNight
37%
900
12%
2700
9%
900
40%
900
17%
2011
December16th to endNight
35%
960
15%
2880
8%
960
41%
960
18%
2107

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
10%8%36%6%35%5%6%8%35%
48005
Night
8%9%37%6%35%5%6%8%35%
46922
Cloud CoverDay
11%8%36%5%35%5%5%8%36%
48006
Night
8%9%47%6%35%5%6%8%36%
46925
TransparencyDay
44%7%15%22%8%1
47658
Night
44%7%14%21%9%1
46773
SeeingDay
14%6%24%29%18%5%
6019
Night
13%5%28%34%16%2
15217

By Month

Percentage Cloud Cover NW (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 15thDay
9%10%48%6%45%46%7%33%
1253
16th to endDay
7%9%49%7%35%6%6%7%31%
1485
February1st to 15thDay
8%10%5%7%7%36%5%5%8%30%
1466
16th to endDay
411%9%9%6%46%48%7%26%
1482
March1st to 15thDay
5%11%5%8%7%36%5%6%8%31%
1854
16th to endDay
10%13%5%7%6%445%5%8%27%
2116
April1st to 15thDay
12%11%5%8%6%35%5%6%7%26%
2251
16th to endDay
14%10%37%6%35%5%5%6%30%
2340
May1st to 15thDay
12%8%36%5%35%449%35%
2521
16th to endDay
20%7%26%6%35%5%5%8%27%
2802
June1st to 15thDay
18%7%25%6%45%6%5%7%30%
2700
16th to endDay
13%5%25%5%36%5%7%8%35%
2700
July1st to 15thDay
8%424435%6%7%9%43%
2700
16th to endDay
6%3134345%7%10%49%
2813
August1st to 15thDay
10%5%25%4245%6%8%43%
2461
16th to endDay
9%2144245%5%9%50%
2483
September1st to 15thDay
13%6%24423445%49%
2150
16th to endDay
10%5%2344435%8%45%
1816
October1st to 15thDay
15%8%37%6%24447%34%
1690
16th to endDay
6%8%37%6%35%5%6%7%38%
1584
November1st to 15thDay
9%10%48%5%45%46%7%32%
1438
16th to endDay
6%11%48%6%35%36%8%34%
1296
December1st to 15thDay
5%13%6%11%8%37%6%5%6%24%
1260
16th to endDay
5%10%410%7%35%6%7%10%27%
1344
January1st to 15thNight
5%11%5%9%8%46%6%5%9%25%
2685
16th to endNight
5%11%5%7%6%345%7%9%33%
2748
February1st to 15thNight
7%11%48%5%45%5%48%34%
2385
16th to endNight
5%10%6%10%8%35%5%5%8%28%
1989
March1st to 15thNight
412%48%7%46%5%7%9%29%
2105
16th to endNight
8%12%5%9%6%46%5%6%8%26%
2103
April1st to 15thNight
11%12%48%6%35%5%6%7%28%
1697
16th to endNight
11%10%47%5%335%5%9%33%
1620
May1st to 15thNight
10%8%36%4335%5%8%39%
1427
16th to endNight
19%7%35%5%435%6%8%30%
1309
June1st to 15thNight
14%7%37%7%46%7%5%7%30%
1260
16th to endNight
11%325%5%26%6%6%9%40%
1260
July1st to 15thNight
7%4235%445%6%10%45%
1260
16th to endNight
5%3143145%7%7%53%
1355
August1st to 15thNight
7%425%4245%7%10%44%
1498
16th to endNight
8%32322345%7%55%
1719
September1st to 15thNight
13%424313447%49%
1809
16th to endNight
9%4144235%5%8%50%
1816
October1st to 15thNight
12%8%36%5%445%5%8%36%
1936
16th to endNight
8%8%26%3345%7%8%40%
2288
November1st to 15thNight
6%11%36%6%36%5%5%7%38%
2409
16th to endNight
6%11%48%5%25%46%8%34%
2664
December1st to 15thNight
5%11%5%10%7%47%5%7%6%28%
2700
16th to endNight
411%5%11%8%46%6%5%6%28%
2880

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 15thDay
8%10%48%5%45%5%5%8%32%
1253
16th to endDay
7%9%49%6%36%6%6%7%31%
1485
February1st to 15thDay
9%11%47%8%37%45%7%30%
1466
16th to endDay
5%11%8%10%6%46%6%7%7%26%
1482
March1st to 15thDay
5%11%5%9%7%36%5%5%7%31%
1854
16th to endDay
10%14%48%6%445%6%7%27%
2117
April1st to 15thDay
11%12%5%7%7%35%5%6%7%27%
2251
16th to endDay
14%10%36%6%35%45%6%31%
2340
May1st to 15thDay
13%7%26%5%345%5%8%36%
2521
16th to endDay
20%6%36%5%35%5%6%8%28%
2802
June1st to 15thDay
18%7%35%5%45%5%5%8%30%
2700
16th to endDay
13%425%5%35%5%5%9%36%
2700
July1st to 15thDay
8%3245%35%6%7%9%44%
2700
16th to endDay
6%313425%5%7%10%49%
2813
August1st to 15thDay
10%425%4245%5%9%43%
2461
16th to endDay
9%31342446%8%50%
2483
September1st to 15thDay
13%5%24423335%50%
2150
16th to endDay
10%6%24434448%46%
1816
October1st to 15thDay
15%8%28%5%2445%7%35%
1690
16th to endDay
7%8%37%6%35%5%6%7%39%
1584
November1st to 15thDay
9%10%5%7%5%45%5%5%7%32%
1438
16th to endDay
6%11%5%6%7%35%5%5%8%34%
1296
December1st to 15thDay
7%14%6%11%7%46%6%46%24%
1260
16th to endDay
410%5%10%6%35%7%7%9%28%
1344
January1st to 15thNight
6%11%6%9%8%5%6%6%5%8%25%
2685
16th to endNight
5%12%48%5%35%5%7%9%32%
2748
February1st to 15thNight
7%10%5%8%5%45%46%8%34%
2385
16th to endNight
5%11%6%9%8%35%5%6%7%30%
1989
March1st to 15thNight
412%5%8%7%46%6%6%8%29%
2105
16th to endNight
9%12%6%8%6%47%5%6%8%26%
2106
April1st to 15thNight
11%11%48%6%36%46%8%28%
1697
16th to endNight
11%9%37%6%345%6%8%33%
1620
May1st to 15thNight
11%7%36%43445%8%39%
1427
16th to endNight
20%6%25%5%4446%8%31%
1309
June1st to 15thNight
14%7%35%6%46%7%6%7%29%
1260
16th to endNight
11%325%5%36%6%7%8%40%
1260
July1st to 15thNight
8%424435%5%6%9%46%
1260
16th to endNight
5%3234245%410%52%
1355
August1st to 15thNight
7%425%5%245%7%9%45%
1498
16th to endNight
8%31422345%8%55%
1719
September1st to 15thNight
13%5%1342335%5%49%
1809
16th to endNight
10%4143335%5%8%50%
1816
October1st to 15thNight
12%8%35%5%35%46%7%36%
1936
16th to endNight
8%8%35%4345%7%8%41%
2288
November1st to 15thNight
5%10%36%6%36%46%7%38%
2409
16th to endNight
6%11%5%7%7%35%46%8%34%
2664
December1st to 15thNight
5%11%5%10%8%46%6%5%7%27%
2700
16th to endNight
5%11%5%10%8%46%5%5%7%28%
2880

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 15thDay
48%6%13%23%5%1
1253
16th to endDay
47%8%12%17%9%3
1485
February1st to 15thDay
51%7%14%18%6%1
1466
16th to endDay
52%8%13%18%6%
1482
March1st to 15thDay
49%8%17%17%6%
1854
16th to endDay
54%7%14%18%5%
2117
April1st to 15thDay
54%7%13%16%7%1
2251
16th to endDay
51%6%12%18%9%1
2340
May1st to 15thDay
44%8%12%23%10%
2521
16th to endDay
52%7%13%20%5%
2807
June1st to 15thDay
51%8%13%19%6%1
2700
16th to endDay
42%8%16%24%6%1
2700
July1st to 15thDay
34%9%20%26%8%1
2541
16th to endDay
28%9%19%28%11%1
2636
August1st to 15thDay
36%7%21%26%6%1
2444
16th to endDay
29%7%18%30%12%1
2483
September1st to 15thDay
36%6%11%24%16%4
2150
16th to endDay
36%6%11%31%10%3
1816
October1st to 15thDay
47%5%13%23%8%1
1690
16th to endDay
41%7%13%28%7%1
1584
November1st to 15thDay
49%7%13%21%7%1
1438
16th to endDay
46%7%17%19%8%1
1296
December1st to 15thDay
58%8%11%15%6%
1260
16th to endDay
47%8%14%19%8%
1344
January1st to 15thNight
54%7%13%16%5%2
2685
16th to endNight
45%7%14%19%10%3
2748
February1st to 15thNight
47%6%13%20%10%1
2396
16th to endNight
50%6%11%20%10%
1989
March1st to 15thNight
48%8%15%20%5%
2105
16th to endNight
54%6%13%17%6%
2106
April1st to 15thNight
53%6%13%16%10%
1697
16th to endNight
47%6%13%22%8%1
1620
May1st to 15thNight
41%7%13%24%12%
1428
16th to endNight
51%7%16%17%5%1
1309
June1st to 15thNight
50%9%13%16%8%
1260
16th to endNight
38%9%19%23%8%
1260
July1st to 15thNight
32%8%21%26%10%
1190
16th to endNight
27%10%16%31%12%1
1269
August1st to 15thNight
32%10%18%26%10%1
1490
16th to endNight
26%7%14%32%16%3
1719
September1st to 15thNight
34%5%12%23%17%5%
1809
16th to endNight
30%6%17%26%14%5%
1816
October1st to 15thNight
44%7%13%20%11%1
1936
16th to endNight
38%8%16%25%10%
2288
November1st to 15thNight
42%8%13%22%11%1
2409
16th to endNight
45%8%17%16%9%2
2664
December1st to 15thNight
53%7%14%18%5%
2700
16th to endNight
53%6%12%21%6%
2880

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 15thDay
15%118%26%18%20%
60
16th to endDay
14%429%21%15%14%
64
February1st to 15thDay
19%8%18%36%16%1
72
16th to endDay
13%7%24%39%14%
141
March1st to 15thDay
10%13%39%28%6%1
270
16th to endDay
11%15%37%21%12%2
288
April1st to 15thDay
16%13%30%28%10%1
269
16th to endDay
23%7%23%29%14%1
270
May1st to 15thDay
15%8%27%24%20%5%
383
16th to endDay
22%417%27%22%5%
517
June1st to 15thDay
19%5%21%32%18%3
495
16th to endDay
13%327%31%18%5%
495
July1st to 15thDay
11%416%32%28%7%
475
16th to endDay
9%425%33%21%5%
482
August1st to 15thDay
12%319%32%24%9%
315
16th to endDay
9%420%34%19%10%
332
September1st to 15thDay
19%5%21%27%19%6%
315
16th to endDay
12%10%23%31%16%5%
256
October1st to 15thDay
20%9%16%31%19%2
144
16th to endDay
8%326%31%27%4
96
November1st to 15thDay
17%6%30%26%14%4
90
16th to endDay
6%6%33%24%15%15%
66
December1st to 15thDay
8%51%25%11%3
60
16th to endDay
12%323%28%26%6%
64
January1st to 15thNight
10%8%32%32%12%2
900
16th to endNight
12%6%32%32%14%1
828
February1st to 15thNight
12%6%23%35%17%2
704
16th to endNight
9%5%27%37%17%3
632
March1st to 15thNight
9%6%36%31%14%1
720
16th to endNight
14%5%30%35%11%1
768
April1st to 15thNight
16%5%31%31%13%1
617
16th to endNight
17%429%33%14%
540
May1st to 15thNight
16%424%34%18%1
444
16th to endNight
22%321%31%20%1
375
June1st to 15thNight
17%324%34%17%2
360
16th to endNight
13%321%41%18%2
360
July1st to 15thNight
9%315%42%28%
340
16th to endNight
7%23%43%23%1
376
August1st to 15thNight
10%215%36%32%3
418
16th to endNight
10%318%40%25%1
573
September1st to 15thNight
17%317%33%25%3
648
16th to endNight
11%226%37%19%2
656
October1st to 15thNight
17%323%33%17%2
660
16th to endNight
13%428%37%13%1
704
November1st to 15thNight
10%7%39%31%9%2
834
16th to endNight
12%5%36%31%10%2
900
December1st to 15thNight
11%6%30%34%15%2
900
16th to endNight
12%431%33%14%3
960
Page generated at 2017-09-16 15:07:02. Version ac04

Copyright 2017 A. Danko


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