Red Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Red Lake clear sky chart from 2005-11-05 to 2017-09-20.

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
30%
16335
10%
46776
6%
16288
34%
16288
16%
35401

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
22%
900
7%
2685
4%
895
26%
895
9%
2238
January16th to endNight
23%
960
7%
2845
3%
960
27%
960
10%
2347
February1st to 15thNight
30%
879
14%
2288
5%
875
35%
875
17%
1741
February16th to endNight
34%
789
12%
2051
6%
789
38%
789
16%
1608
March1st to 15thNight
29%
632
14%
2072
9%
632
34%
632
15%
1521
March16th to endNight
33%
576
16%
2088
13%
576
42%
576
17%
1399
April1st to 15thNight
39%
539
18%
1747
14%
539
47%
539
25%
1083
April16th to endNight
36%
540
16%
1578
8%
540
41%
540
23%
1066
May1st to 15thNight
25%
540
11%
1440
3%
540
28%
540
17%
1085
May16th to endNight
34%
563
6%
1358
4%
561
36%
561
22%
1005
June1st to 15thNight
39%
540
2%
1260
2%
540
40%
540
24%
948
June16th to endNight
45%
540
0%
1260
0%
540
46%
540
29%
890
July1st to 15thNight
48%
510
3%
1190
3%
510
49%
510
38%
786
July16th to endNight
51%
564
9%
1245
5%
531
52%
531
36%
836
August1st to 15thNight
53%
539
13%
1486
6%
536
56%
536
32%
939
August16th to endNight
48%
573
18%
1719
14%
573
52%
573
30%
1070
September1st to 15thNight
42%
540
12%
1800
11%
540
47%
540
23%
1171
September16th to endNight
32%
543
11%
1867
9%
543
37%
543
18%
1277
October1st to 15thNight
25%
660
12%
1980
6%
660
30%
660
16%
1474
October16th to endNight
21%
773
7%
2263
3%
773
24%
773
11%
1846
November1st to 15thNight
16%
875
8%
2451
3%
875
20%
875
10%
2044
November16th to endNight
16%
900
5%
2523
3%
900
18%
900
6%
2223
December1st to 15thNight
19%
900
5%
2700
3%
900
22%
900
7%
2315
December16th to endNight
19%
960
8%
2880
4%
960
23%
960
7%
2489

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
15%10%47%6%35%5%5%6%28%
48088
Night
14%11%5%8%6%35%5%45%28%
46923
Cloud CoverDay
27%9%36%5%34445%24%
48098
Night
26%10%37%6%3444424%
46926
Cloud CoverDay
15%10%47%6%35%5%5%6%28%
48099
Night
14%11%5%8%6%35%5%45%28%
46927
TransparencyDay
55%6%12%18%6%
47752
Night
56%5%11%18%6%
46776
SeeingDay
20%12%31%22%10%3
6319
Night
20%9%30%27%11%1
16336

By Month

Percentage Cloud Cover NE (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%14%8%13%6%47%6%6%6%15%
1253
16th to endDay
11%14%8%12%9%5%6%6%9%5%10%
1375
February1st to 15thDay
6%8%48%7%5%10%8%6%8%24%
1575
16th to endDay
8%12%7%11%9%35%6%7%7%21%
1422
March1st to 15thDay
11%13%5%9%6%25%445%29%
1888
16th to endDay
14%10%47%8%3445%7%28%
2136
April1st to 15thDay
11%9%47%5%35%45%6%36%
2198
16th to endDay
13%8%36%5%3435%7%38%
2382
May1st to 15thDay
20%9%37%6%34446%30%
2511
16th to endDay
22%7%45%5%24445%32%
2753
June1st to 15thDay
20%6%25%5%35%5%6%8%29%
2700
16th to endDay
18%6%36%5%35%6%6%7%28%
2700
July1st to 15thDay
15%5%35%5%35%5%6%7%35%
2700
16th to endDay
14%5%35%5%45%5%6%7%36%
2839
August1st to 15thDay
14%5%36%6%45%5%6%8%34%
2463
16th to endDay
15%7%26%4335%5%8%37%
2482
September1st to 15thDay
17%8%26%5%2445%6%36%
2160
16th to endDay
23%11%35%434345%31%
1847
October1st to 15thDay
20%17%47%5%24345%23%
1650
16th to endDay
24%22%5%8%5%2344416%
1609
November1st to 15thDay
19%17%7%9%6%3434418%
1407
16th to endDay
16%16%6%13%11%5%5%43411%
1434
December1st to 15thDay
8%13%9%13%12%6%7%5%4413%
1260
16th to endDay
12%19%8%13%9%37%45%5%9%
1344
January1st to 15thNight
8%14%6%11%11%5%8%7%6%5%13%
2685
16th to endNight
10%15%7%10%7%5%8%9%6%5%13%
2845
February1st to 15thNight
7%10%5%7%6%5%10%8%5%6%24%
2285
16th to endNight
6%12%5%10%9%47%6%5%5%24%
2051
March1st to 15thNight
13%11%5%8%6%35%5%4432%
2060
16th to endNight
13%12%5%7%5%23335%37%
2088
April1st to 15thNight
10%8%45%5%23446%44%
1747
16th to endNight
12%11%35%5%34335%41%
1578
May1st to 15thNight
21%9%38%5%33345%29%
1440
16th to endNight
22%7%25%42445%7%33%
1357
June1st to 15thNight
19%7%25%5%335%5%6%34%
1260
16th to endNight
14%5%244246%5%9%39%
1260
July1st to 15thNight
10%2145%4447%8%46%
1260
16th to endNight
11%435%424447%47%
1329
August1st to 15thNight
11%4134245%5%7%47%
1495
16th to endNight
13%415%42335%7%47%
1719
September1st to 15thNight
19%6%25%413345%42%
1800
16th to endNight
20%9%25%42445%5%35%
1867
October1st to 15thNight
18%13%36%6%335%45%29%
1980
16th to endNight
22%18%46%5%34345%21%
2263
November1st to 15thNight
18%19%6%10%6%2333420%
2451
16th to endNight
16%17%8%12%10%6%6%33213%
2523
December1st to 15thNight
11%14%7%13%12%6%7%5%4412%
2700
16th to endNight
13%17%8%13%9%46%5%4411%
2880

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
21%11%5%12%5%47%5%5%5%13%
1254
16th to endDay
25%12%5%11%7%35%6%8%48%
1375
February1st to 15thDay
21%8%38%6%48%6%5%7%19%
1575
16th to endDay
22%9%410%8%245%5%6%18%
1422
March1st to 15thDay
24%11%48%424445%25%
1899
16th to endDay
26%10%36%7%34445%24%
2134
April1st to 15thDay
25%8%25%5%2335%5%31%
2198
16th to endDay
28%7%25%432345%30%
2382
May1st to 15thDay
31%7%26%5%33435%26%
2511
16th to endDay
34%6%2432333429%
2753
June1st to 15thDay
33%5%25%43445%5%25%
2700
16th to endDay
32%6%25%5%245%5%5%24%
2700
July1st to 15thDay
29%42442446%6%31%
2700
16th to endDay
29%4245%3445%6%29%
2839
August1st to 15thDay
21%425%7%3445%7%32%
2463
16th to endDay
23%6%25%42345%7%33%
2482
September1st to 15thDay
25%8%35%5%2335%5%31%
2160
16th to endDay
28%9%25%43333431%
1847
October1st to 15thDay
27%16%37%6%24335%21%
1650
16th to endDay
29%20%46%5%3333415%
1609
November1st to 15thDay
31%15%48%43333416%
1407
16th to endDay
30%13%6%12%8%5%43229%
1434
December1st to 15thDay
22%11%5%10%10%6%6%5%4313%
1260
16th to endDay
25%15%6%12%8%26%45%46%
1344
January1st to 15thNight
21%11%410%9%5%7%6%5%410%
2685
16th to endNight
24%13%5%8%6%5%7%8%5%411%
2845
February1st to 15thNight
22%9%46%6%47%7%5%421%
2278
16th to endNight
20%11%48%8%45%5%4423%
2051
March1st to 15thNight
26%10%36%5%245%3327%
2072
16th to endNight
25%10%46%42333430%
2086
April1st to 15thNight
24%7%25%423335%36%
1747
16th to endNight
26%10%25%5%2323433%
1578
May1st to 15thNight
34%7%26%42234426%
1439
16th to endNight
35%5%14422345%29%
1358
June1st to 15thNight
32%7%15%421445%29%
1260
16th to endNight
29%4244135%47%31%
1260
July1st to 15thNight
24%31243435%8%40%
1260
16th to endNight
26%315%323335%40%
1329
August1st to 15thNight
20%4133245%5%6%42%
1495
16th to endNight
20%424423446%42%
1719
September1st to 15thNight
27%6%14423345%37%
1800
16th to endNight
27%8%2442345%5%33%
1867
October1st to 15thNight
27%12%26%5%24435%26%
1980
16th to endNight
28%16%45%5%3333420%
2263
November1st to 15thNight
29%16%5%9%6%2232319%
2451
16th to endNight
29%15%5%10%9%5%332210%
2523
December1st to 15thNight
24%12%410%10%46%5%4312%
2700
16th to endNight
25%14%6%12%8%45%5%448%
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
9%14%8%13%6%5%7%6%6%6%15%
1253
16th to endDay
11%15%7%12%9%5%6%6%9%5%10%
1375
February1st to 15thDay
6%8%48%8%5%10%8%7%8%24%
1575
16th to endDay
8%11%6%11%9%35%6%7%7%21%
1422
March1st to 15thDay
11%13%6%9%6%25%445%29%
1899
16th to endDay
14%11%37%8%345%5%6%28%
2136
April1st to 15thDay
11%9%47%5%35%45%6%37%
2198
16th to endDay
13%8%35%5%3445%7%38%
2382
May1st to 15thDay
19%9%37%6%34445%30%
2511
16th to endDay
21%7%36%5%24445%33%
2753
June1st to 15thDay
20%7%25%5%35%5%6%7%29%
2700
16th to endDay
18%6%36%6%35%6%6%7%29%
2700
July1st to 15thDay
15%5%35%435%5%6%7%35%
2700
16th to endDay
14%5%25%5%36%5%6%8%36%
2839
August1st to 15thDay
13%5%36%7%36%46%8%34%
2463
16th to endDay
15%6%26%4335%6%8%37%
2482
September1st to 15thDay
17%8%36%5%3345%6%35%
2160
16th to endDay
23%10%35%5%33345%31%
1847
October1st to 15thDay
20%16%48%5%34345%23%
1650
16th to endDay
24%22%5%8%5%2343416%
1609
November1st to 15thDay
19%16%7%9%7%3433418%
1407
16th to endDay
16%16%6%14%10%5%5%33411%
1434
December1st to 15thDay
8%13%9%13%12%6%7%6%5%413%
1260
16th to endDay
13%18%8%13%9%37%46%5%9%
1344
January1st to 15thNight
9%14%6%11%10%6%8%7%6%5%13%
2685
16th to endNight
10%15%6%10%7%5%8%8%6%5%13%
2845
February1st to 15thNight
6%11%5%8%6%5%10%8%6%6%24%
2278
16th to endNight
6%12%5%10%9%47%6%5%424%
2051
March1st to 15thNight
13%11%5%8%6%25%5%4431%
2072
16th to endNight
13%12%5%7%5%23335%37%
2088
April1st to 15thNight
10%8%45%5%23346%44%
1747
16th to endNight
11%10%36%5%24335%41%
1578
May1st to 15thNight
21%9%38%5%3335%5%29%
1439
16th to endNight
22%7%34434447%33%
1357
June1st to 15thNight
18%8%16%5%335%5%7%33%
1260
16th to endNight
14%5%244346%5%9%39%
1260
July1st to 15thNight
9%3145%3447%9%46%
1260
16th to endNight
10%426%333447%48%
1329
August1st to 15thNight
11%4134345%5%7%46%
1495
16th to endNight
13%5%15%42345%7%47%
1719
September1st to 15thNight
19%6%25%423345%42%
1800
16th to endNight
21%9%2442445%6%35%
1867
October1st to 15thNight
19%13%36%5%34445%29%
1980
16th to endNight
22%19%5%6%433335%21%
2263
November1st to 15thNight
19%18%7%10%6%2332420%
2451
16th to endNight
16%17%8%12%10%7%5%42212%
2523
December1st to 15thNight
11%14%7%13%12%5%7%5%4412%
2700
16th to endNight
13%17%8%13%9%46%5%4411%
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
66%5%9%15%3
1254
16th to endDay
69%48%12%5%
1375
February1st to 15thDay
54%6%13%18%6%
1576
16th to endDay
58%5%9%19%5%
1422
March1st to 15thDay
55%6%12%17%7%1
1899
16th to endDay
55%5%13%16%6%2
2136
April1st to 15thDay
47%5%10%21%13%2
2198
16th to endDay
45%49%26%11%2
2382
May1st to 15thDay
55%5%9%20%8%
2511
16th to endDay
53%6%9%18%10%1
2757
June1st to 15thDay
51%7%11%17%10%
2700
16th to endDay
51%9%15%16%6%
2700
July1st to 15thDay
43%8%14%25%8%
2541
16th to endDay
46%8%16%22%6%
2660
August1st to 15thDay
45%9%14%24%4
2448
16th to endDay
43%9%18%22%6%
2482
September1st to 15thDay
48%7%16%21%5%
2160
16th to endDay
56%5%13%20%3
1847
October1st to 15thDay
63%5%13%14%3
1650
16th to endDay
72%5%12%9%
1609
November1st to 15thDay
69%410%11%2
1407
16th to endDay
76%49%6%2
1434
December1st to 15thDay
72%410%11%1
1260
16th to endDay
75%46%11%3
1344
January1st to 15thNight
69%5%7%15%2
2685
16th to endNight
67%5%7%14%3
2845
February1st to 15thNight
55%5%11%18%8%
2288
16th to endNight
58%5%9%19%5%
2051
March1st to 15thNight
55%410%16%10%1
2072
16th to endNight
50%412%21%7%3
2088
April1st to 15thNight
40%410%23%17%3
1747
16th to endNight
45%47%21%19%1
1578
May1st to 15thNight
56%49%20%9%
1440
16th to endNight
50%5%10%17%13%2
1358
June1st to 15thNight
49%6%9%19%14%
1260
16th to endNight
40%8%17%24%8%
1260
July1st to 15thNight
33%7%16%30%12%
1190
16th to endNight
35%6%15%31%7%2
1245
August1st to 15thNight
34%7%18%29%9%
1486
16th to endNight
35%7%19%30%7%
1719
September1st to 15thNight
42%6%13%28%7%
1800
16th to endNight
49%5%18%22%4
1867
October1st to 15thNight
56%5%16%18%3
1980
16th to endNight
65%5%13%12%2
2263
November1st to 15thNight
69%410%12%3
2451
16th to endNight
77%49%6%2
2523
December1st to 15thNight
73%5%10%8%2
2700
16th to endNight
75%46%10%3
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
7%11%47%26%6%
90
16th to endDay
26%6%38%18%9%1
96
February1st to 15thDay
17%18%38%16%7%
90
16th to endDay
19%16%39%17%6%1
81
March1st to 15thDay
17%10%40%23%6%2
90
16th to endDay
27%12%36%10%10%1
120
April1st to 15thDay
13%16%29%25%12%1
317
16th to endDay
18%15%33%23%8%1
450
May1st to 15thDay
24%17%29%20%5%2
468
16th to endDay
26%11%29%21%8%2
517
June1st to 15thDay
22%13%31%19%7%4
495
16th to endDay
23%11%25%23%10%4
495
July1st to 15thDay
16%8%34%26%11%4
475
16th to endDay
12%12%29%23%14%7%
515
August1st to 15thDay
16%9%27%25%16%5%
493
16th to endDay
17%9%29%26%13%2
522
September1st to 15thDay
21%7%32%25%10%2
315
16th to endDay
39%13%33%13%
138
October1st to 15thDay
31%12%32%17%6%
90
16th to endDay
39%7%42%7%21
96
November1st to 15thDay
34%7%37%15%4
90
16th to endDay
37%14%28%10%8%
90
December1st to 15thDay
8%11%43%22%10%4
90
16th to endDay
21%11%29%28%7%2
96
January1st to 15thNight
16%13%35%24%8%2
900
16th to endNight
18%11%35%27%6%
960
February1st to 15thNight
13%9%35%27%12%1
880
16th to endNight
12%9%30%32%12%3
789
March1st to 15thNight
18%11%31%25%11%1
632
16th to endNight
18%11%27%25%12%3
576
April1st to 15thNight
14%10%29%32%12%
539
16th to endNight
16%11%29%32%8%1
540
May1st to 15thNight
27%10%31%24%5%1
540
16th to endNight
25%8%26%26%12%
563
June1st to 15thNight
23%7%22%30%15%1
540
16th to endNight
18%325%34%15%1
540
July1st to 15thNight
9%433%33%16%1
510
16th to endNight
12%425%32%20%3
564
August1st to 15thNight
14%321%36%20%2
539
16th to endNight
16%5%24%33%18%1
573
September1st to 15thNight
22%6%25%28%15%2
540
16th to endNight
27%8%27%23%11%
543
October1st to 15thNight
29%8%30%24%6%
660
16th to endNight
31%9%26%22%9%
773
November1st to 15thNight
28%11%33%17%6%2
875
16th to endNight
26%11%32%23%5%
900
December1st to 15thNight
16%8%37%27%8%1
900
16th to endNight
20%10%30%25%10%1
960
Page generated at 2017-09-21 07:18:18. Version ac04

Copyright 2017 A. Danko


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