Salmonberry
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Salmonberry clear sky chart from 2005-11-05 to 2017-10-31.

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%
14812
11%
47085
10%
14783
42%
14783
16%
34729

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
28%
719
8%
2506
7%
716
31%
716
8%
2054
January16th to endNight
33%
768
10%
2574
10%
768
34%
768
11%
2025
February1st to 15thNight
27%
697
5%
2288
4%
697
28%
697
8%
1925
February16th to endNight
27%
632
8%
2026
4%
632
32%
632
9%
1644
March1st to 15thNight
26%
720
4%
2022
3%
720
27%
720
8%
1725
March16th to endNight
22%
768
4%
2097
3%
768
23%
768
7%
1865
April1st to 15thNight
28%
719
5%
1799
3%
719
28%
719
11%
1524
April16th to endNight
39%
572
8%
1652
5%
572
41%
572
14%
1283
May1st to 15thNight
39%
401
12%
1481
11%
401
45%
401
17%
991
May16th to endNight
46%
375
8%
1496
10%
374
49%
374
12%
1089
June1st to 15thNight
44%
360
7%
1411
9%
360
47%
360
15%
965
June16th to endNight
54%
360
12%
1260
13%
360
57%
360
23%
807
July1st to 15thNight
69%
340
16%
1251
21%
340
74%
340
40%
609
July16th to endNight
68%
376
23%
1416
30%
354
77%
354
48%
584
August1st to 15thNight
79%
538
20%
1611
20%
535
80%
535
49%
787
August16th to endNight
69%
635
26%
1781
20%
635
70%
635
43%
982
September1st to 15thNight
70%
720
25%
1800
15%
720
72%
720
51%
1006
September16th to endNight
55%
716
21%
1985
17%
716
57%
716
29%
1277
October1st to 15thNight
47%
720
16%
2160
15%
720
50%
720
24%
1454
October16th to endNight
41%
768
13%
2316
13%
768
42%
768
16%
1734
November1st to 15thNight
26%
700
6%
2425
6%
700
28%
700
7%
2028
November16th to endNight
30%
720
6%
2520
6%
720
31%
720
10%
2012
December1st to 15thNight
32%
720
8%
2520
8%
720
33%
720
9%
2014
December16th to endNight
20%
768
5%
2688
5%
768
21%
768
5%
2345

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
23%13%47%5%2333426%
48685
Night
20%12%47%5%34345%27%
47249
Cloud CoverDay
22%12%47%5%34335%27%
48685
Night
18%11%47%5%34446%29%
47253
TransparencyDay
57%6%10%14%8%2
48352
Night
54%7%11%14%9%2
47086
SeeingDay
24%14%25%22%10%2
6142
Night
22%8%20%29%17%1
14821

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
34%19%46%42232315%
1432
16th to endDay
28%17%46%42323323%
1650
February1st to 15thDay
29%19%5%8%6%3433312%
1576
16th to endDay
27%24%5%8%5%3222314%
1447
March1st to 15thDay
35%20%5%8%5%2332210%
1938
16th to endDay
34%22%6%8%5%232228%
2127
April1st to 15thDay
28%19%7%8%6%2333411%
2149
16th to endDay
29%17%47%7%3433314%
2307
May1st to 15thDay
24%12%47%424435%26%
2469
16th to endDay
27%11%5%8%7%34445%16%
2615
June1st to 15thDay
28%13%47%6%34345%20%
2544
16th to endDay
21%9%5%8%5%24446%26%
2700
July1st to 15thDay
10%7%24313347%51%
2631
16th to endDay
10%6%24323446%51%
2654
August1st to 15thDay
8%6%2442345%7%49%
2340
16th to endDay
10%7%35%423446%47%
2420
September1st to 15thDay
7%6%25%323436%53%
2160
16th to endDay
18%8%38%5%33345%34%
1971
October1st to 15thDay
24%9%37%5%2344429%
1800
16th to endDay
27%11%37%5%24336%24%
1906
November1st to 15thDay
36%12%5%8%6%2443311%
1433
16th to endDay
31%15%5%7%6%3332218%
1440
December1st to 15thDay
28%16%5%9%6%3322319%
1440
16th to endDay
32%20%5%7%6%2322314%
1536
January1st to 15thNight
29%16%5%8%42333317%
2506
16th to endNight
25%14%5%8%5%24335%20%
2574
February1st to 15thNight
23%16%6%11%7%3433414%
2276
16th to endNight
21%19%5%10%5%3323320%
2026
March1st to 15thNight
26%19%6%8%6%2333414%
2022
16th to endNight
27%19%8%9%5%344439%
2093
April1st to 15thNight
22%17%7%9%6%4333417%
1799
16th to endNight
18%14%48%7%2446%7%20%
1652
May1st to 15thNight
16%12%48%5%24447%29%
1481
16th to endNight
18%9%48%7%35%5%5%7%23%
1496
June1st to 15thNight
18%9%5%8%5%35%446%28%
1411
16th to endNight
11%8%36%5%35%5%5%9%35%
1260
July1st to 15thNight
43235%3445%7%54%
1326
16th to endNight
432332335%8%58%
1512
August1st to 15thNight
331332446%9%56%
1620
16th to endNight
5%5%233245%5%8%52%
1781
September1st to 15thNight
5%413323246%61%
1800
16th to endNight
12%6%36%5%2445%7%41%
1985
October1st to 15thNight
17%7%26%6%34445%38%
2160
16th to endNight
22%11%37%6%24345%28%
2316
November1st to 15thNight
32%13%48%6%3333415%
2425
16th to endNight
26%13%5%9%6%3333321%
2520
December1st to 15thNight
24%13%5%7%6%35%43321%
2520
16th to endNight
32%18%6%8%5%2322214%
2688

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
31%18%6%9%42223315%
1432
16th to endDay
26%15%47%5%3423423%
1650
February1st to 15thDay
27%18%7%8%5%35%33313%
1576
16th to endDay
24%22%5%8%6%3322415%
1447
March1st to 15thDay
32%20%5%7%6%2333211%
1938
16th to endDay
32%20%6%10%5%332328%
2127
April1st to 15thDay
28%18%5%9%5%24435%12%
2149
16th to endDay
27%16%47%6%35%43416%
2307
May1st to 15thDay
23%11%47%5%24335%28%
2469
16th to endDay
26%9%48%6%35%45%6%17%
2615
June1st to 15thDay
26%12%46%5%345%45%22%
2544
16th to endDay
21%8%47%6%3445%7%27%
2700
July1st to 15thDay
10%6%24313436%53%
2631
16th to endDay
9%5%24323347%52%
2654
August1st to 15thDay
9%5%23424447%50%
2340
16th to endDay
9%6%25%42335%6%48%
2420
September1st to 15thDay
8%424424436%53%
2160
16th to endDay
18%7%37%5%34445%35%
1971
October1st to 15thDay
24%8%37%6%23445%30%
1800
16th to endDay
26%10%37%5%34436%25%
1906
November1st to 15thDay
33%14%46%7%26%335%12%
1433
16th to endDay
28%15%5%8%5%35%22319%
1440
December1st to 15thDay
25%14%5%9%6%3433319%
1440
16th to endDay
29%19%5%7%6%2322315%
1536
January1st to 15thNight
26%14%7%8%5%2434417%
2506
16th to endNight
22%14%48%6%34346%21%
2574
February1st to 15thNight
19%15%6%10%9%4444416%
2276
16th to endNight
19%17%5%9%6%45%33421%
2026
March1st to 15thNight
22%17%6%9%6%3434415%
2022
16th to endNight
23%18%6%11%7%3444411%
2097
April1st to 15thNight
21%15%6%10%6%44345%17%
1799
16th to endNight
16%13%46%6%35%45%8%23%
1652
May1st to 15thNight
15%10%36%6%3445%6%32%
1481
16th to endNight
16%8%46%6%35%6%6%8%26%
1496
June1st to 15thNight
17%9%46%5%3445%7%31%
1411
16th to endNight
11%7%35%435%46%9%38%
1260
July1st to 15thNight
42134245%5%7%57%
1326
16th to endNight
331232235%8%61%
1512
August1st to 15thNight
421232435%9%59%
1620
16th to endNight
5%31441345%9%55%
1781
September1st to 15thNight
5%323223346%64%
1800
16th to endNight
11%5%25%5%25%45%8%42%
1985
October1st to 15thNight
15%7%25%5%3445%6%39%
2160
16th to endNight
21%9%36%6%2445%5%30%
2316
November1st to 15thNight
28%13%48%6%34445%16%
2425
16th to endNight
23%11%5%8%7%3444421%
2520
December1st to 15thNight
22%13%5%8%6%35%44421%
2520
16th to endNight
28%18%5%9%6%2432314%
2688

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
74%36%7%7%1
1432
16th to endDay
65%5%6%9%7%5%
1650
February1st to 15thDay
75%5%8%7%2
1576
16th to endDay
74%5%6%8%5%
1447
March1st to 15thDay
79%5%5%6%3
1938
16th to endDay
83%446%
2127
April1st to 15thDay
73%6%10%8%1
2149
16th to endDay
71%6%8%8%4
2307
May1st to 15thDay
55%6%12%17%6%
2469
16th to endDay
64%9%11%11%2
2619
June1st to 15thDay
62%8%12%11%5%
2544
16th to endDay
52%9%13%16%6%2
2700
July1st to 15thDay
31%5%13%24%19%4
2477
16th to endDay
26%6%13%25%21%5%
2487
August1st to 15thDay
30%7%17%24%15%4
2324
16th to endDay
33%6%13%26%15%4
2420
September1st to 15thDay
28%7%12%21%21%9%
2160
16th to endDay
49%6%11%16%13%3
1971
October1st to 15thDay
54%6%10%16%9%2
1800
16th to endDay
60%7%7%13%11%
1906
November1st to 15thDay
74%6%8%7%2
1433
16th to endDay
71%5%5%7%9%
1440
December1st to 15thDay
70%6%5%10%6%
1440
16th to endDay
75%47%7%4
1536
January1st to 15thNight
68%6%7%8%7%2
2506
16th to endNight
64%5%7%8%8%5%
2574
February1st to 15thNight
68%7%8%10%31
2288
16th to endNight
65%6%9%10%6%
2026
March1st to 15thNight
71%6%8%10%3
2022
16th to endNight
75%6%8%8%1
2097
April1st to 15thNight
67%6%11%10%3
1799
16th to endNight
57%8%13%13%5%1
1652
May1st to 15thNight
48%6%15%19%8%1
1482
16th to endNight
50%12%15%15%5%
1496
June1st to 15thNight
48%8%18%18%5%
1411
16th to endNight
39%9%21%22%5%2
1260
July1st to 15thNight
21%8%16%26%20%6%
1251
16th to endNight
15%5%17%31%19%10%
1416
August1st to 15thNight
17%7%22%29%17%6%
1611
16th to endNight
23%7%16%30%16%5%
1781
September1st to 15thNight
20%6%14%24%23%11%
1800
16th to endNight
36%8%14%18%15%5%
1985
October1st to 15thNight
43%6%11%21%14%3
2160
16th to endNight
54%7%9%14%12%2
2316
November1st to 15thNight
68%7%9%9%4
2425
16th to endNight
64%6%8%8%10%1
2520
December1st to 15thNight
64%7%8%11%8%
2520
16th to endNight
76%5%6%7%4
2688

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
28%11%21%18%18%1
60
16th to endDay
35%12%20%19%11%
178
February1st to 15thDay
42%15%20%14%6%
236
16th to endDay
38%25%19%12%2
216
March1st to 15thDay
47%23%19%7%2
270
16th to endDay
48%18%20%9%21
288
April1st to 15thDay
29%20%24%14%9%2
269
16th to endDay
39%15%23%14%42
270
May1st to 15thDay
27%21%23%18%7%1
288
16th to endDay
24%12%23%23%12%3
330
June1st to 15thDay
25%17%27%20%9%
339
16th to endDay
16%15%33%25%6%1
495
July1st to 15thDay
9%6%30%39%10%2
411
16th to endDay
7%7%33%36%13%2
327
August1st to 15thDay
10%6%26%34%16%6%
315
16th to endDay
8%7%26%31%20%5%
332
September1st to 15thDay
10%11%25%31%17%3
315
16th to endDay
17%12%25%29%14%
315
October1st to 15thDay
26%15%22%21%13%1
315
16th to endDay
32%11%22%17%12%3
324
November1st to 15thDay
27%12%38%15%41
65
16th to endDay
33%11%26%13%11%3
60
December1st to 15thDay
40%25%23%11%
60
16th to endDay
31%12%23%20%12%
64
January1st to 15thNight
31%12%19%20%14%1
720
16th to endNight
28%7%19%23%17%3
768
February1st to 15thNight
25%11%22%24%13%1
704
16th to endNight
27%12%22%24%12%
632
March1st to 15thNight
31%15%18%21%11%
720
16th to endNight
31%14%20%23%8%1
768
April1st to 15thNight
28%12%21%24%11%1
719
16th to endNight
21%9%20%34%13%1
572
May1st to 15thNight
17%9%25%27%18%
402
16th to endNight
17%5%19%38%17%
375
June1st to 15thNight
18%323%40%13%
360
16th to endNight
11%5%23%40%17%
360
July1st to 15thNight
3119%51%24%
340
16th to endNight
3121%48%23%1
376
August1st to 15thNight
5%9%45%36%3
538
16th to endNight
8%115%43%28%2
635
September1st to 15thNight
6%215%39%30%4
720
16th to endNight
12%317%39%23%2
716
October1st to 15thNight
18%5%21%29%21%3
720
16th to endNight
27%7%17%24%20%2
768
November1st to 15thNight
32%9%22%24%10%
700
16th to endNight
28%10%21%23%14%2
720
December1st to 15thNight
29%10%20%25%12%1
720
16th to endNight
35%12%22%16%10%1
768
Page generated at 2017-11-01 14:23:41. Version ac04

Copyright 2017 A. Danko


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