Kalama
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kalama 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
40%
22519
12%
74389
10%
22475
43%
22475
16%
54398

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
24%
760
7%
2646
6%
756
26%
756
7%
2234
January11th to 20thNight
31%
732
8%
2562
9%
732
32%
732
9%
2056
January21st to endNight
36%
792
11%
2637
11%
792
37%
792
11%
2090
February1st to 10thNight
29%
720
7%
2340
6%
720
31%
720
8%
1964
February11th to 20thNight
30%
700
8%
2274
7%
700
34%
700
11%
1815
February21st to endNight
29%
592
9%
1865
7%
592
31%
592
10%
1527
March1st to 10thNight
29%
720
8%
2074
6%
720
31%
720
12%
1695
March11th to 20thNight
31%
720
10%
1980
7%
720
34%
720
12%
1621
March21st to endNight
28%
792
5%
2134
4%
792
29%
792
8%
1840
April1st to 10thNight
29%
720
6%
1800
3%
720
31%
720
12%
1505
April11th to 20thNight
35%
695
10%
1763
5%
695
36%
695
15%
1412
April21st to endNight
39%
540
9%
1620
6%
540
41%
540
14%
1230
May1st to 10thNight
43%
388
13%
1468
13%
388
49%
388
19%
957
May11th to 20thNight
50%
354
11%
1416
13%
354
54%
354
16%
956
May21st to endNight
43%
389
8%
1552
9%
388
49%
388
14%
1086
June1st to 10thNight
44%
360
8%
1440
11%
360
46%
360
16%
961
June11th to 20thNight
45%
360
8%
1360
9%
360
49%
360
19%
906
June21st to endNight
55%
360
17%
1260
19%
360
61%
360
35%
668
July1st to 10thNight
63%
350
17%
1280
19%
350
70%
350
39%
640
July11th to 20thNight
59%
348
22%
1392
26%
348
71%
348
39%
651
July21st to endNight
70%
394
28%
1488
33%
372
82%
372
54%
579
August1st to 10thNight
74%
491
22%
1557
18%
489
81%
489
50%
725
August11th to 20thNight
76%
534
28%
1602
23%
534
79%
534
50%
773
August21st to endNight
59%
705
28%
1893
17%
705
63%
705
41%
1090
September1st to 10thNight
59%
720
26%
1800
14%
720
63%
720
45%
1046
September11th to 20thNight
55%
720
21%
1800
13%
720
57%
720
31%
1205
September21st to endNight
54%
720
20%
2063
16%
720
57%
720
29%
1305
October1st to 10thNight
52%
720
14%
2160
14%
720
55%
720
25%
1428
October11th to 20thNight
49%
720
17%
2160
16%
720
52%
720
21%
1513
October21st to endNight
37%
792
14%
2425
11%
792
42%
792
17%
1757
November1st to 10thNight
32%
740
9%
2526
9%
740
35%
740
10%
2030
November11th to 20thNight
29%
760
8%
2660
6%
760
33%
760
9%
2143
November21st to endNight
34%
760
7%
2660
7%
760
36%
760
11%
2068
December1st to 10thNight
33%
760
10%
2660
9%
760
35%
760
10%
2096
December11th to 20thNight
25%
759
7%
3232
6%
759
26%
759
6%
2676
December21st to endNight
18%
832
3%
4840
5%
817
20%
817
3%
4150

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
21%10%47%6%3445%6%30%
75114
Night
21%10%47%6%34446%32%
74638
TransparencyDay
57%5%11%16%9%2
74815
Night
56%5%11%17%9%2
74455
SeeingDay
26%11%26%25%10%2
13841
Night
29%6%17%32%16%1
22528

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 10thDay
37%14%6%8%6%3344311%
1519
11th to 20thDay
32%13%48%5%23325%21%
1459
21st to endDay
28%13%5%9%7%4444420%
1714
February1st to 10thDay
32%14%5%8%5%35%446%14%
1620
11th to 20thDay
31%14%6%8%6%33435%16%
1575
21st to endDay
30%15%5%8%5%44445%16%
1390
March1st to 10thDay
28%14%5%9%7%4445%5%14%
1884
11th to 20thDay
31%13%5%8%6%35%43417%
1980
21st to endDay
30%14%5%11%7%46%5%5%410%
2222
April1st to 10thDay
29%14%5%9%6%3445%5%15%
2160
11th to 20thDay
27%13%5%8%6%345%4421%
2144
21st to endDay
23%11%5%7%8%46%45%6%22%
2340
May1st to 10thDay
18%9%48%7%45%5%45%33%
2491
11th to 20thDay
19%9%48%7%45%5%6%7%27%
2477
21st to endDay
23%8%47%7%36%6%6%6%24%
2723
June1st to 10thDay
22%9%47%6%345%47%28%
2520
11th to 20thDay
20%9%48%7%46%5%6%8%22%
2594
21st to endDay
10%7%35%6%45%5%6%7%43%
2700
July1st to 10thDay
8%5%36%6%3445%6%51%
2638
11th to 20thDay
9%5%2443445%7%53%
2520
21st to endDay
6%32332335%7%63%
2741
August1st to 10thDay
6%5%35%5%2445%7%53%
2372
11th to 20thDay
7%4134235%47%59%
2298
21st to endDay
9%7%35%5%35%5%6%7%47%
2462
September1st to 10thDay
8%6%25%42446%6%52%
2160
11th to 20thDay
12%6%48%6%46%447%40%
2160
21st to endDay
17%7%25%6%3445%6%40%
1893
October1st to 10thDay
21%8%27%5%45%5%46%32%
1800
11th to 20thDay
22%8%38%6%4445%7%29%
1800
21st to endDay
27%11%47%6%3335%426%
1930
November1st to 10thDay
29%12%5%9%6%45%6%5%5%13%
1549
11th to 20thDay
34%12%47%5%25%445%18%
1520
21st to endDay
31%12%5%8%6%3434420%
1520
December1st to 10thDay
26%14%48%6%45%44421%
1520
11th to 20thDay
27%12%5%10%9%45%45%5%14%
1925
21st to endDay
28%16%5%10%9%45%5%4411%
2794
January1st to 10thNight
36%12%48%5%35%43417%
2646
11th to 20thNight
32%12%47%6%34445%20%
2562
21st to endNight
28%12%5%7%6%35%436%22%
2637
February1st to 10thNight
28%15%5%9%7%35%5%35%17%
2340
11th to 20thNight
24%15%5%8%5%34345%23%
2272
21st to endNight
26%14%5%8%7%445%4419%
1865
March1st to 10thNight
25%14%5%7%7%35%445%21%
2074
11th to 20thNight
27%12%47%6%36%46%5%21%
1979
21st to endNight
29%14%49%5%45%5%5%6%15%
2134
April1st to 10thNight
25%13%5%9%7%34445%22%
1800
11th to 20thNight
21%11%5%8%6%45%45%6%25%
1763
21st to endNight
22%11%46%6%345%5%7%28%
1620
May1st to 10thNight
14%10%37%5%345%36%39%
1468
11th to 20thNight
16%6%45%5%36%6%6%9%34%
1416
21st to endNight
12%8%46%8%45%6%5%8%35%
1552
June1st to 10thNight
16%8%38%7%34446%37%
1440
11th to 20thNight
15%8%35%6%3445%9%38%
1360
21st to endNight
9%5%24332347%58%
1260
July1st to 10thNight
43135%335%5%7%62%
1318
11th to 20thNight
4313423446%64%
1440
21st to endNight
3211212246%76%
1576
August1st to 10thNight
421322345%8%68%
1565
11th to 20thNight
4213323347%70%
1602
21st to endNight
8%4245%2345%6%57%
1893
September1st to 10thNight
7%323423445%63%
1800
11th to 20thNight
10%6%46%6%35%35%6%46%
1800
21st to endNight
11%5%25%6%3445%8%46%
2063
October1st to 10thNight
17%7%26%5%34446%42%
2160
11th to 20thNight
20%7%36%5%345%5%6%36%
2160
21st to endNight
26%8%36%6%33445%32%
2425
November1st to 10thNight
30%11%48%6%35%45%5%21%
2526
11th to 20thNight
32%10%47%6%35%44420%
2660
21st to endNight
27%12%37%6%35%445%24%
2660
December1st to 10thNight
26%12%47%6%35%5%46%22%
2660
11th to 20thNight
27%14%5%9%8%45%445%16%
3280
21st to endNight
27%16%6%10%7%5%6%5%4412%
4862

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
80%46%5%5%1
1519
11th to 20thDay
68%410%8%7%3
1459
21st to endDay
68%5%8%11%7%1
1714
February1st to 10thDay
73%410%10%4
1620
11th to 20thDay
73%47%10%5%1
1584
21st to endDay
73%38%9%6%1
1390
March1st to 10thDay
72%49%9%6%
1884
11th to 20thDay
71%48%13%31
1980
21st to endDay
79%48%9%
2222
April1st to 10thDay
73%410%11%2
2160
11th to 20thDay
68%5%9%11%6%1
2144
21st to endDay
66%411%12%6%1
2340
May1st to 10thDay
55%414%19%7%
2491
11th to 20thDay
58%6%15%16%5%1
2480
21st to endDay
62%6%14%15%2
2724
June1st to 10thDay
59%5%17%13%6%
2520
11th to 20thDay
61%5%18%12%3
2594
21st to endDay
42%5%17%24%9%3
2700
July1st to 10thDay
38%5%13%24%16%4
2567
11th to 20thDay
34%410%28%21%3
2445
21st to endDay
23%310%33%27%4
2589
August1st to 10thDay
32%415%27%18%4
2355
11th to 20thDay
26%5%15%32%17%5%
2298
21st to endDay
38%5%11%30%14%2
2462
September1st to 10thDay
32%413%25%18%7%
2160
11th to 20thDay
45%6%12%15%16%5%
2160
21st to endDay
47%5%14%17%15%4
1893
October1st to 10thDay
54%49%21%11%2
1800
11th to 20thDay
53%6%14%16%10%1
1800
21st to endDay
61%47%15%12%
1930
November1st to 10thDay
72%5%8%11%3
1549
11th to 20thDay
69%5%11%8%5%2
1520
21st to endDay
68%46%9%12%
1520
December1st to 10thDay
67%7%6%12%7%2
1520
11th to 20thDay
73%49%12%2
1928
21st to endDay
78%39%7%3
2794
January1st to 10thNight
73%49%7%42
2646
11th to 20thNight
68%410%10%6%3
2562
21st to endNight
66%48%13%8%1
2637
February1st to 10thNight
71%6%8%12%31
2340
11th to 20thNight
66%5%11%10%7%2
2274
21st to endNight
69%410%9%7%
1865
March1st to 10thNight
66%6%10%14%4
2074
11th to 20thNight
66%5%10%11%6%1
1980
21st to endNight
72%6%11%10%1
2134
April1st to 10thNight
68%412%12%4
1800
11th to 20thNight
61%6%10%13%7%2
1763
21st to endNight
58%6%14%15%5%1
1620
May1st to 10thNight
48%5%16%21%9%1
1468
11th to 20thNight
50%6%18%19%5%2
1416
21st to endNight
51%9%17%18%5%
1552
June1st to 10thNight
50%5%16%23%4
1440
11th to 20thNight
48%6%23%20%3
1360
21st to endNight
29%423%30%10%4
1260
July1st to 10thNight
25%5%18%29%18%6%
1280
11th to 20thNight
25%412%31%24%5%
1392
21st to endNight
15%211%38%25%9%
1488
August1st to 10thNight
19%420%32%19%5%
1557
11th to 20thNight
19%418%36%16%7%
1602
21st to endNight
29%412%34%18%3
1893
September1st to 10thNight
27%413%29%19%9%
1800
11th to 20thNight
42%412%21%14%7%
1800
21st to endNight
39%5%15%20%17%4
2063
October1st to 10thNight
46%311%24%14%2
2160
11th to 20thNight
50%5%11%19%13%1
2160
21st to endNight
54%5%10%17%13%1
2425
November1st to 10thNight
68%48%13%6%1
2526
11th to 20thNight
68%49%10%5%3
2660
21st to endNight
64%47%12%11%1
2660
December1st to 10thNight
65%6%8%13%8%1
2660
11th to 20thNight
71%5%9%10%5%
3276
21st to endNight
78%47%8%2
4862

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
46%10%23%12%7%3
180
11th to 20thDay
43%16%20%12%5%4
165
21st to endDay
38%8%20%22%10%2
306
February1st to 10thDay
45%10%19%16%8%1
340
11th to 20thDay
44%11%23%16%5%1
335
21st to endDay
39%15%24%15%7%
306
March1st to 10thDay
36%16%26%15%6%
420
11th to 20thDay
35%13%24%18%9%2
420
21st to endDay
38%16%22%16%8%1
462
April1st to 10thDay
37%14%21%20%7%2
420
11th to 20thDay
33%22%22%15%7%2
412
21st to endDay
29%15%29%20%7%1
420
May1st to 10thDay
21%17%27%23%10%2
423
11th to 20thDay
30%12%23%24%10%1
448
21st to endDay
25%11%28%25%10%2
485
June1st to 10thDay
27%10%25%28%10%1
450
11th to 20thDay
22%17%34%20%5%1
524
21st to endDay
12%9%36%32%11%1
630
July1st to 10thDay
11%7%33%36%11%2
562
11th to 20thDay
9%9%30%36%14%3
444
21st to endDay
6%332%39%18%2
487
August1st to 10thDay
10%424%44%13%4
447
11th to 20thDay
5%425%42%21%4
437
21st to endDay
10%8%36%32%12%2
495
September1st to 10thDay
13%6%32%35%13%2
450
11th to 20thDay
18%8%22%34%16%2
450
21st to endDay
22%12%23%31%11%2
450
October1st to 10thDay
27%9%24%25%12%2
450
11th to 20thDay
29%8%21%24%16%2
450
21st to endDay
33%14%22%18%11%2
445
November1st to 10thDay
34%16%24%20%6%
210
11th to 20thDay
40%11%19%18%10%2
180
21st to endDay
32%18%23%12%15%1
180
December1st to 10thDay
33%14%21%18%12%1
180
11th to 20thDay
44%13%24%12%6%1
180
21st to endDay
42%13%23%14%8%1
198
January1st to 10thNight
45%8%16%17%12%2
760
11th to 20thNight
42%7%12%23%14%1
732
21st to endNight
36%5%11%29%17%2
792
February1st to 10thNight
40%7%12%29%12%1
720
11th to 20thNight
35%8%16%28%13%
704
21st to endNight
38%8%15%27%12%
592
March1st to 10thNight
37%8%16%25%13%1
720
11th to 20thNight
35%8%16%29%12%1
720
21st to endNight
39%10%13%26%11%1
792
April1st to 10thNight
35%8%18%24%14%1
720
11th to 20thNight
29%9%18%30%13%2
695
21st to endNight
28%6%17%33%16%1
540
May1st to 10thNight
21%7%22%34%15%1
388
11th to 20thNight
23%417%36%18%1
354
21st to endNight
18%6%21%36%19%1
389
June1st to 10thNight
23%320%39%14%
360
11th to 20thNight
19%7%22%39%12%1
360
21st to endNight
14%224%46%14%
360
July1st to 10thNight
7%420%52%17%1
350
11th to 20thNight
5%127%51%14%
348
21st to endNight
5%221%57%16%
394
August1st to 10thNight
5%215%49%26%2
491
11th to 20thNight
6%112%45%34%2
534
21st to endNight
12%321%43%20%1
705
September1st to 10thNight
10%322%43%20%2
720
11th to 20thNight
17%5%14%34%28%3
720
21st to endNight
16%419%40%19%2
720
October1st to 10thNight
22%314%40%19%2
720
11th to 20thNight
27%414%31%22%3
720
21st to endNight
33%6%17%26%17%1
792
November1st to 10thNight
37%9%16%29%10%
740
11th to 20thNight
41%8%14%24%11%1
760
21st to endNight
35%8%15%25%15%2
760
December1st to 10thNight
35%8%16%26%13%2
760
11th to 20thNight
41%8%18%22%10%1
760
21st to endNight
47%9%18%18%8%1
836
Page generated at 2024-01-10 16:35:25. Version ac07

Copyright 2024 Attilla Danko


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