Fort Frances
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fort Frances clear sky chart from 2005-11-05 to 2018-08-29.

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
31%
17558
12%
50453
6%
17512
36%
17512
17%
36800

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
25%
975
9%
2910
6%
970
29%
970
12%
2280
January16th to endNight
17%
1040
8%
2924
1%
1040
22%
1040
10%
2378
February1st to 15thNight
27%
954
13%
2483
4%
951
31%
951
17%
1835
February16th to endNight
29%
851
12%
2217
5%
851
34%
851
17%
1695
March1st to 15thNight
29%
653
15%
2213
10%
653
35%
653
15%
1568
March16th to endNight
29%
624
15%
2262
11%
624
38%
624
14%
1553
April1st to 15thNight
28%
584
16%
1939
11%
584
38%
584
17%
1310
April16th to endNight
29%
579
15%
1723
8%
579
38%
579
15%
1224
May1st to 15thNight
32%
585
14%
1560
5%
585
37%
585
21%
1120
May16th to endNight
40%
611
11%
1597
3%
609
44%
609
23%
1106
June1st to 15thNight
37%
585
7%
1365
3%
585
40%
585
26%
951
June16th to endNight
43%
585
6%
1365
3%
585
45%
585
26%
961
July1st to 15thNight
51%
555
11%
1295
6%
555
53%
555
39%
810
July16th to endNight
49%
612
16%
1452
6%
579
55%
579
35%
896
August1st to 15thNight
56%
575
20%
1631
12%
572
60%
572
35%
951
August16th to endNight
49%
615
22%
1879
17%
615
57%
615
31%
1098
September1st to 15thNight
48%
540
16%
1800
14%
540
54%
540
26%
1059
September16th to endNight
35%
583
16%
1981
13%
583
40%
583
20%
1307
October1st to 15thNight
31%
720
16%
2160
10%
720
36%
720
19%
1480
October16th to endNight
24%
792
11%
2394
5%
792
30%
792
13%
1842
November1st to 15thNight
22%
950
10%
2661
5%
950
26%
950
14%
2075
November16th to endNight
19%
975
9%
2730
5%
975
23%
975
9%
2252
December1st to 15thNight
18%
975
6%
2792
3%
975
22%
975
8%
2369
December16th to endNight
17%
1040
7%
3120
3%
1040
22%
1040
7%
2680

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%9%47%5%35%5%5%6%32%
51820
Night
13%10%47%6%35%45%6%32%
50607
Cloud CoverDay
15%9%47%6%35%5%5%6%32%
51831
Night
13%10%47%6%35%45%6%32%
50611
Cloud CoverDay
15%9%37%5%35%45%6%32%
51829
Night
14%10%47%6%35%446%32%
50611
TransparencyDay
51%6%12%20%7%
51492
Night
52%6%12%20%8%
50453
SeeingDay
18%13%25%24%13%4
7538
Night
16%18%25%26%11%1
17559

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
12%12%6%10%6%446%5%7%21%
1358
16th to endDay
11%13%6%11%9%47%6%6%6%14%
1648
February1st to 15thDay
8%10%5%10%7%38%8%5%6%24%
1710
16th to endDay
10%12%6%9%6%45%5%36%27%
1542
March1st to 15thDay
10%13%5%7%6%3445%6%33%
2076
16th to endDay
15%10%47%5%335%47%32%
2314
April1st to 15thDay
13%8%36%5%35%5%5%7%35%
2337
16th to endDay
18%10%34434446%34%
2512
May1st to 15thDay
20%9%36%5%34446%30%
2721
16th to endDay
18%6%25%42445%7%36%
2867
June1st to 15thDay
18%5%35%6%35%5%5%7%33%
2925
16th to endDay
17%5%36%6%35%6%5%7%32%
2925
July1st to 15thDay
12%424435%45%8%42%
2925
16th to endDay
11%5%25%436%6%5%8%41%
2976
August1st to 15thDay
11%5%245%345%7%9%40%
2571
16th to endDay
12%5%25%5%3445%8%42%
2619
September1st to 15thDay
12%6%35%43445%7%42%
2160
16th to endDay
20%5%26%423446%37%
1966
October1st to 15thDay
20%11%37%5%33445%31%
1800
16th to endDay
23%14%46%5%2333427%
1830
November1st to 15thDay
16%14%8%8%5%3444425%
1527
16th to endDay
14%16%8%14%8%5%443416%
1560
December1st to 15thDay
13%17%6%12%9%5%8%6%4412%
1495
16th to endDay
14%16%9%14%9%46%36%312%
1456
January1st to 15thNight
10%13%6%10%8%46%6%6%421%
2910
16th to endNight
11%14%6%10%8%5%6%5%6%6%17%
2924
February1st to 15thNight
8%8%410%7%46%6%5%6%30%
2480
16th to endNight
9%10%5%10%7%46%5%45%28%
2217
March1st to 15thNight
11%10%48%5%35%446%33%
2201
16th to endNight
15%9%46%6%3435%5%35%
2262
April1st to 15thNight
15%9%37%5%2445%6%35%
1939
16th to endNight
18%9%35%5%3444436%
1723
May1st to 15thNight
20%7%25%42445%7%35%
1560
16th to endNight
17%6%2441445%7%40%
1595
June1st to 15thNight
17%5%25%42345%6%43%
1365
16th to endNight
14%5%145%2445%8%41%
1365
July1st to 15thNight
8%224425%45%9%51%
1365
16th to endNight
7%22442335%8%53%
1544
August1st to 15thNight
8%41342335%8%53%
1640
16th to endNight
11%42442335%7%52%
1879
September1st to 15thNight
12%414423446%50%
1800
16th to endNight
16%8%35%433446%40%
1981
October1st to 15thNight
16%9%45%42445%7%35%
2160
16th to endNight
19%13%37%5%35%446%26%
2394
November1st to 15thNight
16%15%5%7%6%34346%25%
2661
16th to endNight
16%14%6%10%8%45%435%19%
2730
December1st to 15thNight
11%14%6%12%10%5%7%5%5%5%13%
2792
16th to endNight
16%15%7%13%9%35%5%45%12%
3120

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
13%12%6%9%7%45%6%5%8%21%
1358
16th to endDay
12%13%7%11%9%47%6%7%6%13%
1648
February1st to 15thDay
7%10%5%10%7%38%8%5%7%24%
1710
16th to endDay
10%12%5%9%6%45%5%36%27%
1542
March1st to 15thDay
10%13%5%7%6%3445%6%33%
2087
16th to endDay
16%10%37%5%33446%32%
2314
April1st to 15thDay
13%9%36%6%35%45%7%35%
2337
16th to endDay
18%10%345%34445%34%
2512
May1st to 15thDay
20%9%36%6%25%346%30%
2721
16th to endDay
18%6%25%5%25%447%37%
2867
June1st to 15thDay
18%5%25%6%35%5%5%7%33%
2925
16th to endDay
17%6%26%5%35%6%6%7%31%
2925
July1st to 15thDay
13%434435%5%5%8%41%
2925
16th to endDay
11%5%25%435%6%5%8%41%
2976
August1st to 15thDay
11%5%15%5%35%6%6%9%39%
2571
16th to endDay
12%5%25%5%3445%8%42%
2619
September1st to 15thDay
13%5%26%5%2435%7%42%
2160
16th to endDay
21%6%26%423446%37%
1966
October1st to 15thDay
20%11%37%6%23346%30%
1800
16th to endDay
23%14%46%6%2333427%
1830
November1st to 15thDay
16%15%8%8%5%2444425%
1527
16th to endDay
14%15%7%14%8%45%33416%
1560
December1st to 15thDay
13%16%6%12%9%5%8%6%4413%
1495
16th to endDay
14%16%8%14%9%46%35%411%
1456
January1st to 15thNight
10%13%6%10%8%46%6%6%421%
2910
16th to endNight
10%15%6%10%8%46%6%5%6%17%
2924
February1st to 15thNight
8%9%410%6%5%6%5%5%7%30%
2473
16th to endNight
10%9%5%10%9%36%5%45%28%
2217
March1st to 15thNight
11%11%47%6%35%446%34%
2213
16th to endNight
16%9%47%6%24445%35%
2262
April1st to 15thNight
14%9%37%5%34446%35%
1939
16th to endNight
18%9%35%5%3443436%
1723
May1st to 15thNight
21%6%25%42345%7%35%
1559
16th to endNight
18%5%25%42345%8%39%
1595
June1st to 15thNight
17%425%42345%7%42%
1365
16th to endNight
14%6%24425%45%9%41%
1365
July1st to 15thNight
8%314425%45%8%52%
1365
16th to endNight
7%215%32336%9%53%
1544
August1st to 15thNight
9%413423448%54%
1640
16th to endNight
11%41432335%8%51%
1879
September1st to 15thNight
12%5%23423446%50%
1800
16th to endNight
16%8%35%423346%40%
1981
October1st to 15thNight
16%10%45%33435%6%36%
2160
16th to endNight
20%12%36%6%35%436%26%
2394
November1st to 15thNight
17%15%5%7%6%24346%25%
2661
16th to endNight
16%14%6%10%7%45%445%20%
2730
December1st to 15thNight
11%14%6%12%10%5%7%5%5%5%14%
2792
16th to endNight
16%15%8%13%10%35%5%45%12%
3120

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 15thDay
13%12%5%10%7%36%5%5%7%22%
1358
16th to endDay
11%13%6%11%9%5%6%7%6%5%14%
1648
February1st to 15thDay
7%11%410%7%38%8%5%6%25%
1710
16th to endDay
11%12%5%9%6%5%5%5%45%28%
1542
March1st to 15thDay
10%13%5%7%6%3445%6%33%
2087
16th to endDay
16%10%37%5%34346%33%
2312
April1st to 15thDay
12%9%26%5%35%5%5%6%35%
2337
16th to endDay
18%10%35%5%34346%35%
2512
May1st to 15thDay
20%8%36%5%35%445%30%
2721
16th to endDay
17%6%35%425%45%7%37%
2867
June1st to 15thDay
17%6%25%6%35%5%5%7%34%
2925
16th to endDay
17%6%36%5%445%6%7%33%
2925
July1st to 15thDay
13%42443446%8%42%
2925
16th to endDay
11%5%25%425%5%5%8%42%
2976
August1st to 15thDay
11%5%25%435%5%6%8%41%
2571
16th to endDay
12%5%245%3445%7%42%
2619
September1st to 15thDay
12%6%26%42345%7%43%
2160
16th to endDay
21%5%26%42335%6%37%
1966
October1st to 15thDay
20%11%37%42335%432%
1800
16th to endDay
23%14%45%5%2333427%
1830
November1st to 15thDay
17%15%8%7%5%2344424%
1527
16th to endDay
15%16%7%14%9%4423415%
1560
December1st to 15thDay
13%16%6%12%9%5%8%5%4412%
1495
16th to endDay
14%16%8%15%8%46%35%412%
1456
January1st to 15thNight
11%13%6%10%8%46%6%6%5%21%
2910
16th to endNight
11%14%6%10%8%46%5%6%6%17%
2924
February1st to 15thNight
8%9%310%6%5%6%6%5%6%30%
2473
16th to endNight
10%10%5%10%8%36%5%46%28%
2217
March1st to 15thNight
11%11%47%6%35%445%33%
2213
16th to endNight
16%9%36%6%23446%34%
2262
April1st to 15thNight
14%9%37%5%24447%36%
1939
16th to endNight
18%9%35%5%3433436%
1723
May1st to 15thNight
21%7%25%33445%6%35%
1559
16th to endNight
18%6%2342445%7%40%
1595
June1st to 15thNight
17%5%24423446%43%
1365
16th to endNight
14%5%24434448%42%
1365
July1st to 15thNight
8%223425%35%10%50%
1365
16th to endNight
8%31432436%8%53%
1544
August1st to 15thNight
8%31432435%7%53%
1640
16th to endNight
10%42441325%7%52%
1879
September1st to 15thNight
12%5%13423446%50%
1800
16th to endNight
17%7%245%24336%40%
1981
October1st to 15thNight
18%9%35%434346%35%
2160
16th to endNight
20%12%46%6%35%446%26%
2394
November1st to 15thNight
18%15%6%7%6%23345%25%
2661
16th to endNight
16%14%6%10%9%45%44319%
2730
December1st to 15thNight
11%14%6%13%11%5%6%5%5%6%13%
2792
16th to endNight
15%15%8%13%9%35%5%45%12%
3120

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
60%6%10%17%5%
1359
16th to endDay
67%6%10%12%3
1648
February1st to 15thDay
56%8%10%17%7%
1711
16th to endDay
59%411%20%4
1542
March1st to 15thDay
51%6%13%19%8%
2087
16th to endDay
53%5%14%18%7%2
2314
April1st to 15thDay
47%5%10%19%16%1
2337
16th to endDay
52%48%21%12%
2512
May1st to 15thDay
55%5%10%21%7%
2721
16th to endDay
46%6%11%22%12%
2871
June1st to 15thDay
49%8%12%21%7%
2925
16th to endDay
49%8%14%19%7%
2925
July1st to 15thDay
38%8%12%28%12%
2766
16th to endDay
39%7%15%26%9%
2805
August1st to 15thDay
39%8%17%25%6%1
2556
16th to endDay
40%6%15%28%9%
2619
September1st to 15thDay
40%6%14%30%7%
2160
16th to endDay
47%6%16%24%5%
1966
October1st to 15thDay
54%6%13%19%6%
1800
16th to endDay
61%5%11%16%4
1830
November1st to 15thDay
61%6%11%14%5%
1527
16th to endDay
71%6%7%10%3
1560
December1st to 15thDay
72%7%7%9%2
1495
16th to endDay
75%47%8%4
1456
January1st to 15thNight
61%5%9%16%5%
2910
16th to endNight
64%6%10%15%2
2924
February1st to 15thNight
51%5%14%19%8%
2483
16th to endNight
56%5%11%20%6%
2217
March1st to 15thNight
51%6%10%19%10%
2213
16th to endNight
51%412%19%9%1
2262
April1st to 15thNight
47%5%9%20%14%1
1939
16th to endNight
51%47%18%16%1
1723
May1st to 15thNight
49%5%11%22%11%
1560
16th to endNight
43%6%11%23%13%2
1597
June1st to 15thNight
40%6%13%24%13%
1365
16th to endNight
40%7%17%24%8%1
1365
July1st to 15thNight
28%6%15%33%14%
1295
16th to endNight
29%7%14%32%14%1
1452
August1st to 15thNight
28%6%15%32%14%1
1631
16th to endNight
32%5%15%32%13%
1879
September1st to 15thNight
34%6%16%31%10%
1800
16th to endNight
46%5%15%27%6%
1981
October1st to 15thNight
46%6%13%25%7%
2160
16th to endNight
59%6%11%19%3
2394
November1st to 15thNight
60%5%12%15%5%
2661
16th to endNight
66%6%11%10%4
2730
December1st to 15thNight
69%7%10%10%2
2792
16th to endNight
73%5%7%10%2
3120

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
17%11%27%26%16%
135
16th to endDay
24%5%34%27%5%2
144
February1st to 15thDay
12%14%43%25%3
135
16th to endDay
30%6%42%15%31
120
March1st to 15thDay
14%8%26%28%17%4
135
16th to endDay
21%10%24%22%14%5%
170
April1st to 15thDay
13%16%31%25%11%1
336
16th to endDay
22%18%24%21%11%
511
May1st to 15thDay
23%19%23%21%9%2
543
16th to endDay
21%15%21%24%11%4
597
June1st to 15thDay
18%17%26%23%10%2
570
16th to endDay
18%16%18%24%16%5%
570
July1st to 15thDay
15%12%22%29%15%5%
550
16th to endDay
12%15%20%25%17%7%
595
August1st to 15thDay
11%10%20%28%20%8%
549
16th to endDay
16%9%22%26%18%6%
555
September1st to 15thDay
15%10%24%30%16%2
315
16th to endDay
24%10%28%25%7%2
180
October1st to 15thDay
22%11%24%23%11%5%
135
16th to endDay
34%6%29%22%6%1
144
November1st to 15thDay
24%7%37%20%8%1
135
16th to endDay
34%14%27%16%6%1
135
December1st to 15thDay
23%7%33%25%9%
135
16th to endDay
15%6%38%24%11%2
144
January1st to 15thNight
13%22%28%22%11%1
975
16th to endNight
16%21%33%23%5%
1040
February1st to 15thNight
11%20%29%26%10%1
955
16th to endNight
12%18%27%26%11%3
851
March1st to 15thNight
13%20%27%26%10%1
653
16th to endNight
17%21%22%23%11%3
624
April1st to 15thNight
16%19%29%24%9%
584
16th to endNight
21%20%20%26%10%
579
May1st to 15thNight
20%18%24%28%7%
585
16th to endNight
17%18%19%30%11%1
611
June1st to 15thNight
17%18%22%30%10%
585
16th to endNight
14%17%18%29%18%
585
July1st to 15thNight
9%12%21%34%20%
555
16th to endNight
9%17%20%30%20%2
612
August1st to 15thNight
9%10%18%34%24%2
575
16th to endNight
12%11%22%32%18%2
615
September1st to 15thNight
15%11%22%31%17%2
540
16th to endNight
19%13%28%23%14%1
583
October1st to 15thNight
21%16%26%26%8%
720
16th to endNight
24%15%29%23%5%1
792
November1st to 15thNight
22%19%28%22%5%1
950
16th to endNight
19%23%29%21%4
975
December1st to 15thNight
16%21%30%21%8%
975
16th to endNight
20%20%25%22%8%2
1040
Page generated at 2018-08-30 04:34:23. Version ac04

Copyright 2018 A. Danko


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