Fort Providence
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fort Providence clear sky chart from 2005-11-05 to 2019-06-19.

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
39%
17625
7%
53748
5%
17599
41%
17599
15%
40280

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
31%
1107
7%
3696
6%
1105
33%
1105
10%
2935
January16th to endNight
33%
1184
9%
3584
7%
1184
35%
1184
11%
2879
February1st to 15thNight
39%
912
12%
3048
10%
912
44%
912
15%
2140
February16th to endNight
35%
736
9%
2530
9%
736
37%
736
11%
1942
March1st to 15thNight
42%
840
16%
2520
12%
840
45%
840
19%
1750
March16th to endNight
44%
896
11%
2356
6%
896
46%
896
24%
1640
April1st to 15thNight
40%
674
11%
1934
9%
674
44%
674
20%
1338
April16th to endNight
42%
416
3%
1605
2%
416
43%
416
19%
987
May1st to 15thNight
42%
419
0%
1329
0%
419
42%
419
22%
865
May16th to endNight
48%
438
0%
1118
0%
438
48%
438
30%
740
June1st to 15thNight
45%
420
0%
840
0%
420
45%
420
26%
638
June16th to endNight
53%
398
0%
796
0%
398
53%
398
29%
589
July1st to 15thNight
51%
370
0%
740
0%
370
51%
370
29%
554
July16th to endNight
58%
408
0%
1074
0%
386
61%
386
29%
680
August1st to 15thNight
58%
384
0%
1238
0%
382
58%
382
25%
773
August16th to endNight
50%
428
3%
1670
3%
428
51%
428
16%
1124
September1st to 15thNight
45%
708
7%
1878
5%
708
47%
708
22%
1333
September16th to endNight
40%
776
9%
2115
5%
776
43%
776
18%
1571
October1st to 15thNight
40%
780
10%
2447
8%
780
42%
780
16%
1789
October16th to endNight
29%
894
5%
2878
3%
894
31%
894
9%
2371
November1st to 15thNight
30%
1033
6%
3103
4%
1033
33%
1033
10%
2523
November16th to endNight
32%
1110
4%
3545
3%
1110
33%
1110
8%
2912
December1st to 15thNight
31%
1110
5%
3672
4%
1110
32%
1110
8%
3003
December16th to endNight
37%
1184
7%
4032
6%
1184
39%
1184
9%
3204

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%9%47%6%45%5%6%7%32%
55059
Night
9%11%5%9%7%45%5%5%7%27%
53847
TransparencyDay
48%8%17%19%5%
54663
Night
54%7%15%17%4
53748
SeeingDay
13%13%20%28%18%5%
9680
Night
13%15%16%29%20%4
17634

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
8%16%410%12%46%348%19%
902
16th to endDay
7%14%7%11%10%46%5%6%6%18%
1344
February1st to 15thDay
47%5%9%8%5%5%6%7%11%27%
1489
16th to endDay
6%11%7%11%7%5%6%6%6%7%22%
1516
March1st to 15thDay
5%10%6%9%6%345%8%8%29%
2100
16th to endDay
6%11%46%5%35%5%5%8%36%
2572
April1st to 15thDay
7%10%36%6%35%446%39%
2671
16th to endDay
47%48%7%46%6%6%7%36%
2959
May1st to 15thDay
8%7%46%5%345%6%6%39%
3281
16th to endDay
13%5%2432445%8%44%
3697
June1st to 15thDay
11%6%37%6%46%5%6%8%33%
3780
16th to endDay
10%6%35%6%46%6%6%10%33%
3572
July1st to 15thDay
10%5%36%7%5%6%6%7%8%32%
3510
16th to endDay
8%6%25%6%36%6%7%8%35%
3375
August1st to 15thDay
11%6%25%6%45%5%5%7%38%
2968
16th to endDay
18%8%26%6%45%6%47%30%
2883
September1st to 15thDay
16%7%26%5%345%5%8%33%
2412
16th to endDay
15%11%36%5%36%45%7%28%
2175
October1st to 15thDay
11%14%5%9%6%45%5%47%25%
1843
16th to endDay
15%18%7%8%6%34445%21%
1683
November1st to 15thDay
13%17%7%11%8%3444420%
1411
16th to endDay
11%16%6%9%9%48%5%4419%
1075
December1st to 15thDay
12%14%8%11%9%5%5%46%5%18%
945
16th to endDay
7%15%5%12%10%46%47%5%19%
896
January1st to 15thNight
10%15%7%12%7%35%5%5%7%18%
3696
16th to endNight
7%13%7%12%9%47%5%5%6%20%
3584
February1st to 15thNight
47%5%10%9%46%7%6%8%28%
3036
16th to endNight
6%15%5%11%8%5%6%5%45%24%
2530
March1st to 15thNight
310%6%10%7%35%45%6%35%
2520
16th to endNight
6%10%47%6%45%45%8%37%
2352
April1st to 15thNight
7%11%36%7%445%5%5%36%
1934
16th to endNight
46%46%7%36%6%5%8%38%
1605
May1st to 15thNight
6%5%46%6%36%6%6%8%37%
1328
16th to endNight
13%5%344226%5%7%43%
1118
June1st to 15thNight
9%6%37%6%35%5%6%7%37%
840
16th to endNight
7%336%6%35%8%7%9%37%
796
July1st to 15thNight
9%426%8%45%7%8%11%32%
780
16th to endNight
5%5%25%5%35%6%7%12%40%
1144
August1st to 15thNight
8%5%24425%5%7%8%44%
1244
16th to endNight
12%7%26%5%45%6%6%8%34%
1670
September1st to 15thNight
14%7%25%5%345%6%9%35%
1878
16th to endNight
14%10%37%6%245%6%8%30%
2115
October1st to 15thNight
11%12%37%6%35%446%32%
2447
16th to endNight
14%19%6%9%6%35%446%19%
2878
November1st to 15thNight
15%14%6%12%8%34445%21%
3103
16th to endNight
11%16%7%11%8%45%5%6%5%16%
3545
December1st to 15thNight
8%14%8%11%9%46%5%5%6%17%
3672
16th to endNight
7%14%7%12%10%5%6%6%5%6%18%
4032

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
64%410%14%5%
902
16th to endDay
65%6%11%12%4
1344
February1st to 15thDay
48%7%17%21%5%
1489
16th to endDay
58%7%13%16%4
1516
March1st to 15thDay
49%6%16%22%41
2100
16th to endDay
44%7%17%22%6%
2572
April1st to 15thDay
45%5%17%24%7%
2671
16th to endDay
43%7%15%26%6%
2959
May1st to 15thDay
42%6%16%24%10%
3281
16th to endDay
37%5%13%29%12%1
3702
June1st to 15thDay
44%8%15%24%6%
3780
16th to endDay
42%9%19%21%6%
3572
July1st to 15thDay
46%10%19%20%3
3321
16th to endDay
39%11%25%21%1
3182
August1st to 15thDay
43%9%22%20%4
2949
16th to endDay
53%9%19%16%1
2883
September1st to 15thDay
48%9%23%16%2
2412
16th to endDay
52%9%22%14%1
2175
October1st to 15thDay
58%8%16%15%1
1843
16th to endDay
65%7%16%8%1
1683
November1st to 15thDay
67%6%16%7%2
1411
16th to endDay
67%7%14%8%2
1075
December1st to 15thDay
67%6%12%11%2
945
16th to endDay
63%7%12%13%3
896
January1st to 15thNight
63%6%10%14%4
3696
16th to endNight
63%7%10%14%4
3584
February1st to 15thNight
49%7%14%21%6%
3048
16th to endNight
59%7%12%17%3
2530
March1st to 15thNight
47%6%14%24%6%
2520
16th to endNight
44%6%16%25%6%
2356
April1st to 15thNight
45%6%13%24%7%1
1934
16th to endNight
40%7%15%23%12%
1605
May1st to 15thNight
41%7%17%20%12%
1329
16th to endNight
37%6%11%30%12%2
1118
June1st to 15thNight
42%9%12%25%9%
840
16th to endNight
37%9%21%24%6%
796
July1st to 15thNight
41%9%22%22%3
740
16th to endNight
32%10%29%24%2
1074
August1st to 15thNight
34%10%25%26%3
1238
16th to endNight
45%10%20%21%1
1670
September1st to 15thNight
43%9%22%20%3
1878
16th to endNight
49%9%20%17%2
2115
October1st to 15thNight
51%8%19%18%1
2447
16th to endNight
65%8%15%9%
2878
November1st to 15thNight
65%6%13%11%3
3103
16th to endNight
66%7%14%10%1
3545
December1st to 15thNight
65%8%14%10%
3672
16th to endNight
63%7%12%13%3
4032

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%9%17%35%17%5%
120
16th to endDay
23%411%31%22%6%
128
February1st to 15thDay
45%34%29%21%5%
120
16th to endDay
6%9%27%32%18%4
143
March1st to 15thDay
8%14%19%25%20%11%
390
16th to endDay
10%15%25%32%13%2
416
April1st to 15thDay
14%16%21%25%16%4
389
16th to endDay
10%15%24%29%16%3
437
May1st to 15thDay
12%19%23%24%16%3
758
16th to endDay
12%16%19%32%15%3
897
June1st to 15thDay
15%15%21%29%14%4
855
16th to endDay
10%15%15%30%21%5%
786
July1st to 15thDay
11%11%18%31%20%6%
735
16th to endDay
9%15%13%27%25%7%
799
August1st to 15thDay
11%10%13%30%24%10%
648
16th to endDay
22%10%23%27%13%3
396
September1st to 15thDay
21%12%22%21%16%5%
375
16th to endDay
15%10%27%25%16%4
375
October1st to 15thDay
20%10%24%25%17%2
268
16th to endDay
33%5%17%28%11%3
157
November1st to 15thDay
10%226%35%16%8%
120
16th to endDay
23%220%40%10%3
120
December1st to 15thDay
23%223%30%16%3
120
16th to endDay
10%16%25%29%17%
128
January1st to 15thNight
14%15%18%28%17%4
1110
16th to endNight
13%16%18%30%17%3
1184
February1st to 15thNight
6%17%18%30%20%5%
916
16th to endNight
12%16%17%30%19%2
736
March1st to 15thNight
6%18%19%28%21%5%
840
16th to endNight
8%16%17%31%22%3
896
April1st to 15thNight
10%19%20%27%20%2
674
16th to endNight
7%19%22%28%19%1
416
May1st to 15thNight
8%19%24%29%16%2
420
16th to endNight
11%16%17%32%20%1
439
June1st to 15thNight
10%16%15%31%22%3
420
16th to endNight
8%16%11%30%29%3
398
July1st to 15thNight
9%12%14%31%27%4
370
16th to endNight
7%16%10%29%31%5%
408
August1st to 15thNight
11%9%13%25%29%9%
384
16th to endNight
15%9%15%29%23%6%
428
September1st to 15thNight
18%12%15%28%18%6%
708
16th to endNight
17%12%19%29%18%2
776
October1st to 15thNight
16%12%19%32%17%2
780
16th to endNight
24%10%18%24%17%4
894
November1st to 15thNight
18%15%15%28%18%4
1033
16th to endNight
17%16%12%29%18%5%
1110
December1st to 15thNight
14%16%18%31%15%3
1110
16th to endNight
12%15%11%26%28%5%
1184
Page generated at 2019-06-20 06:02:30. Version ac04

Copyright 2019 A. Danko


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