Nipigon
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Nipigon clear sky chart from 2005-11-05 to 2017-11-30.

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%
16126
11%
47786
6%
16079
36%
16079
17%
34904

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
24%
900
9%
2506
4%
895
29%
895
14%
1947
January16th to endNight
22%
960
10%
2688
3%
960
29%
960
12%
2137
February1st to 15thNight
29%
879
12%
2392
4%
875
35%
875
19%
1761
February16th to endNight
31%
660
15%
1922
8%
660
36%
660
17%
1395
March1st to 15thNight
33%
720
16%
2160
9%
720
38%
720
21%
1471
March16th to endNight
36%
621
19%
2013
13%
621
45%
621
21%
1317
April1st to 15thNight
33%
539
14%
1797
10%
539
40%
539
19%
1227
April16th to endNight
39%
540
15%
1620
9%
540
44%
540
23%
1086
May1st to 15thNight
32%
540
10%
1440
6%
540
35%
540
20%
1060
May16th to endNight
39%
530
9%
1465
6%
528
41%
528
20%
1057
June1st to 15thNight
35%
360
5%
1260
4%
360
38%
360
17%
848
June16th to endNight
36%
360
5%
1260
5%
360
38%
360
18%
852
July1st to 15thNight
47%
457
6%
1307
5%
457
48%
457
26%
855
July16th to endNight
51%
564
12%
1417
6%
531
52%
531
32%
924
August1st to 15thNight
53%
539
16%
1431
10%
536
57%
536
33%
911
August16th to endNight
42%
573
15%
1789
11%
573
47%
573
25%
1136
September1st to 15thNight
46%
540
14%
1800
10%
540
50%
540
23%
1156
September16th to endNight
34%
699
13%
1962
9%
699
37%
699
21%
1378
October1st to 15thNight
27%
720
13%
2134
6%
720
34%
720
18%
1518
October16th to endNight
23%
768
8%
2496
4%
768
28%
768
10%
1963
November1st to 15thNight
21%
822
8%
2533
4%
822
25%
822
10%
2008
November16th to endNight
20%
975
7%
2832
4%
975
23%
975
9%
2383
December1st to 15thNight
22%
900
5%
2700
1%
900
25%
900
9%
2187
December16th to endNight
23%
960
8%
2862
4%
960
27%
960
9%
2327

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%36%5%35%45%7%32%
48627
Night
15%9%46%6%35%45%7%31%
47954
Cloud CoverDay
15%8%36%6%345%5%7%32%
48637
Night
15%10%47%6%35%45%7%30%
47959
Cloud CoverDay
14%9%47%6%35%5%5%7%31%
48636
Night
14%10%47%6%35%5%5%7%29%
47959
TransparencyDay
50%7%13%19%8%
48312
Night
52%6%13%19%7%
47787
SeeingDay
20%12%34%20%9%2
6391
Night
20%9%30%28%10%1
16127

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
14%11%49%6%5%5%6%6%7%22%
1432
16th to endDay
11%11%410%7%5%6%6%7%9%20%
1536
February1st to 15thDay
8%10%38%6%35%6%8%9%29%
1470
16th to endDay
6%9%5%8%7%5%6%5%6%9%29%
1551
March1st to 15thDay
12%11%5%7%5%34345%34%
1790
16th to endDay
15%9%36%5%35%46%6%34%
2220
April1st to 15thDay
13%8%36%5%345%46%36%
2151
16th to endDay
17%10%35%42435%7%34%
2337
May1st to 15thDay
19%8%36%6%35%45%5%31%
2511
16th to endDay
18%8%35%5%2445%7%34%
2650
June1st to 15thDay
19%6%25%42445%7%36%
2700
16th to endDay
17%6%35%5%35%45%8%34%
2700
July1st to 15thDay
12%5%36%435%5%6%8%38%
2570
16th to endDay
12%5%245%35%5%5%9%39%
2655
August1st to 15thDay
10%4245%35%5%6%8%41%
2520
16th to endDay
15%5%145%2445%7%42%
2410
September1st to 15thDay
14%6%26%6%34347%38%
2160
16th to endDay
19%7%36%5%23447%34%
1986
October1st to 15thDay
20%11%46%5%24448%27%
1825
16th to endDay
23%12%49%6%445%47%18%
1728
November1st to 15thDay
20%12%5%7%7%3445%6%21%
1654
16th to endDay
19%13%6%11%8%45%34418%
1452
December1st to 15thDay
12%11%5%10%8%37%46%8%20%
1260
16th to endDay
15%17%6%13%7%25%445%15%
1359
January1st to 15thNight
13%12%5%9%7%35%5%5%8%23%
2506
16th to endNight
11%12%5%11%9%37%5%5%7%20%
2688
February1st to 15thNight
8%9%46%7%5%7%7%6%8%28%
2390
16th to endNight
7%11%6%9%6%45%6%5%7%30%
1922
March1st to 15thNight
12%10%37%5%35%35%7%36%
2147
16th to endNight
12%8%445%345%5%6%39%
2013
April1st to 15thNight
14%9%45%5%35%46%6%34%
1797
16th to endNight
17%8%3433345%6%38%
1620
May1st to 15thNight
20%8%45%425%446%33%
1440
16th to endNight
19%7%36%434437%34%
1463
June1st to 15thNight
19%6%26%5%24446%36%
1260
16th to endNight
17%6%35%5%335%6%8%34%
1260
July1st to 15thNight
13%5%36%4345%5%6%42%
1387
16th to endNight
8%5%25%425%5%6%9%44%
1513
August1st to 15thNight
9%4245%345%6%6%46%
1440
16th to endNight
15%6%2342345%8%43%
1789
September1st to 15thNight
14%5%25%43436%7%41%
1800
16th to endNight
19%6%35%424446%37%
1962
October1st to 15thNight
16%9%345%2445%6%36%
2134
16th to endNight
22%11%46%6%35%446%23%
2496
November1st to 15thNight
20%13%6%5%6%3445%6%23%
2533
16th to endNight
19%13%6%10%7%45%35%5%18%
2832
December1st to 15thNight
14%13%5%9%7%35%46%7%20%
2700
16th to endNight
16%14%6%9%7%45%45%6%19%
2862

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%48%7%5%6%6%6%7%21%
1432
16th to endDay
11%11%49%7%5%6%6%8%9%19%
1536
February1st to 15thDay
8%10%47%6%346%9%8%29%
1470
16th to endDay
6%10%47%7%5%5%5%6%8%30%
1551
March1st to 15thDay
12%10%6%7%6%34346%34%
1800
16th to endDay
15%9%35%6%35%46%5%34%
2220
April1st to 15thDay
13%8%45%5%345%5%7%35%
2151
16th to endDay
16%10%35%42445%7%35%
2337
May1st to 15thDay
19%7%46%6%35%45%431%
2511
16th to endDay
18%7%35%5%2445%7%34%
2650
June1st to 15thDay
19%5%26%4245%5%7%36%
2700
16th to endDay
16%6%35%5%35%45%8%34%
2700
July1st to 15thDay
12%5%35%5%345%6%8%39%
2570
16th to endDay
11%5%246%345%6%9%39%
2655
August1st to 15thDay
10%4245%35%7%6%8%41%
2520
16th to endDay
15%5%244245%5%6%41%
2410
September1st to 15thDay
14%6%25%6%35%35%7%38%
2160
16th to endDay
20%7%35%5%23447%33%
1986
October1st to 15thDay
19%11%47%5%23447%27%
1825
16th to endDay
23%12%5%9%6%4445%7%17%
1728
November1st to 15thDay
20%13%5%7%6%25%5%6%5%21%
1654
16th to endDay
19%13%5%12%7%35%446%16%
1452
December1st to 15thDay
12%11%5%9%8%37%5%7%8%18%
1260
16th to endDay
14%18%7%13%7%3445%5%15%
1359
January1st to 15thNight
13%12%5%9%7%35%5%5%8%23%
2506
16th to endNight
11%11%5%10%9%46%6%5%7%20%
2688
February1st to 15thNight
8%9%46%7%47%6%7%8%28%
2383
16th to endNight
6%11%6%9%7%45%6%5%7%30%
1922
March1st to 15thNight
12%9%46%5%35%45%7%35%
2160
16th to endNight
12%8%445%3446%6%39%
2013
April1st to 15thNight
14%9%45%5%35%5%5%6%34%
1797
16th to endNight
18%8%25%42346%6%37%
1620
May1st to 15thNight
20%8%35%435%446%33%
1439
16th to endNight
19%8%35%5%24446%34%
1463
June1st to 15thNight
18%6%37%5%35%45%6%35%
1260
16th to endNight
17%7%26%5%35%46%7%34%
1260
July1st to 15thNight
13%5%25%4245%5%7%41%
1387
16th to endNight
8%5%35%435%5%6%8%44%
1513
August1st to 15thNight
9%5%144445%6%6%45%
1440
16th to endNight
15%6%2442435%8%42%
1789
September1st to 15thNight
13%5%25%5%2445%7%41%
1800
16th to endNight
19%6%25%5%14346%37%
1962
October1st to 15thNight
16%10%245%245%5%6%36%
2134
16th to endNight
21%13%36%6%45%446%22%
2496
November1st to 15thNight
19%14%5%7%435%5%5%7%21%
2533
16th to endNight
19%14%5%11%7%4435%6%17%
2832
December1st to 15thNight
14%14%5%8%8%35%45%8%19%
2700
16th to endNight
16%15%48%8%35%45%6%19%
2862

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
12%13%48%8%47%7%6%8%18%
1432
16th to endDay
10%11%5%8%9%47%6%7%9%19%
1536
February1st to 15thDay
8%9%48%6%35%6%9%9%28%
1470
16th to endDay
6%10%48%8%45%5%6%8%30%
1551
March1st to 15thDay
11%11%6%6%5%44346%34%
1800
16th to endDay
14%9%35%6%35%45%6%34%
2219
April1st to 15thDay
12%8%35%5%345%5%7%36%
2151
16th to endDay
16%11%35%424447%35%
2337
May1st to 15thDay
19%7%46%6%35%445%31%
2511
16th to endDay
17%7%35%5%3445%7%34%
2650
June1st to 15thDay
18%6%25%435%45%7%35%
2700
16th to endDay
16%6%36%5%345%5%7%34%
2700
July1st to 15thDay
11%5%37%5%35%46%7%38%
2570
16th to endDay
11%425%5%346%6%9%38%
2655
August1st to 15thDay
9%5%25%5%35%6%6%8%41%
2520
16th to endDay
13%6%245%345%6%6%41%
2410
September1st to 15thDay
14%6%28%5%245%47%37%
2160
16th to endDay
18%9%35%6%245%46%33%
1986
October1st to 15thDay
18%12%47%5%33447%26%
1825
16th to endDay
22%13%410%7%4445%6%16%
1728
November1st to 15thDay
20%13%5%8%6%45%45%5%20%
1654
16th to endDay
19%12%6%11%9%35%35%5%15%
1452
December1st to 15thDay
11%11%6%9%8%47%6%7%8%17%
1260
16th to endDay
13%18%8%12%8%345%5%5%14%
1359
January1st to 15thNight
12%12%5%9%7%35%5%6%8%21%
2506
16th to endNight
11%11%6%10%9%45%6%5%8%19%
2688
February1st to 15thNight
8%9%46%7%47%6%7%8%27%
2383
16th to endNight
6%11%6%9%7%46%5%5%8%30%
1922
March1st to 15thNight
11%9%36%5%35%447%36%
2160
16th to endNight
12%9%35%4345%5%6%39%
2013
April1st to 15thNight
14%9%35%6%345%5%6%33%
1797
16th to endNight
18%8%244245%5%6%37%
1620
May1st to 15thNight
19%8%45%5%25%445%33%
1439
16th to endNight
18%8%45%5%2345%6%34%
1463
June1st to 15thNight
17%6%37%6%35%446%35%
1260
16th to endNight
16%6%35%5%35%6%5%7%34%
1260
July1st to 15thNight
13%6%35%425%5%5%7%40%
1387
16th to endNight
8%6%25%425%6%6%8%43%
1513
August1st to 15thNight
9%4245%35%5%6%7%45%
1440
16th to endNight
14%5%25%5%23449%43%
1789
September1st to 15thNight
12%6%35%5%25%46%8%41%
1800
16th to endNight
18%6%36%424446%37%
1962
October1st to 15thNight
16%9%36%5%335%47%34%
2134
16th to endNight
21%12%47%7%45%446%21%
2496
November1st to 15thNight
19%14%6%7%5%345%6%6%20%
2533
16th to endNight
19%13%6%11%8%3445%5%16%
2832
December1st to 15thNight
13%14%6%8%8%46%46%7%18%
2700
16th to endNight
15%14%6%9%7%46%5%5%5%19%
2862

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
61%6%13%15%3
1433
16th to endDay
58%7%12%15%5%
1536
February1st to 15thDay
47%7%15%20%8%
1471
16th to endDay
50%6%13%20%8%
1551
March1st to 15thDay
52%5%11%20%10%1
1800
16th to endDay
49%6%11%18%11%2
2220
April1st to 15thDay
45%7%10%22%10%2
2151
16th to endDay
49%5%9%20%13%2
2337
May1st to 15thDay
53%7%8%20%9%1
2511
16th to endDay
48%7%12%19%10%
2654
June1st to 15thDay
46%6%11%20%13%
2700
16th to endDay
46%7%13%25%6%
2700
July1st to 15thDay
41%8%13%24%12%
2421
16th to endDay
40%8%14%27%7%
2488
August1st to 15thDay
36%9%16%27%8%
2505
16th to endDay
40%8%15%26%9%
2410
September1st to 15thDay
45%7%15%23%7%
2160
16th to endDay
51%6%17%19%4
1986
October1st to 15thDay
56%6%15%17%3
1825
16th to endDay
67%6%11%12%2
1728
November1st to 15thDay
64%7%12%11%3
1654
16th to endDay
70%7%10%8%3
1452
December1st to 15thDay
62%9%17%8%2
1260
16th to endDay
71%6%10%9%2
1359
January1st to 15thNight
58%6%14%17%2
2506
16th to endNight
62%5%11%14%5%
2688
February1st to 15thNight
51%6%14%19%7%
2393
16th to endNight
51%7%11%22%7%
1922
March1st to 15thNight
47%413%21%11%1
2160
16th to endNight
44%5%13%22%11%3
2013
April1st to 15thNight
48%6%8%22%12%1
1797
16th to endNight
45%5%11%21%14%2
1620
May1st to 15thNight
52%410%19%10%2
1440
16th to endNight
50%5%11%21%9%1
1465
June1st to 15thNight
49%5%8%21%12%2
1260
16th to endNight
48%6%14%22%7%
1260
July1st to 15thNight
40%7%14%25%12%
1307
16th to endNight
35%8%16%29%10%
1417
August1st to 15thNight
34%7%17%29%9%
1431
16th to endNight
40%6%16%27%9%
1789
September1st to 15thNight
40%8%16%25%9%
1800
16th to endNight
46%6%17%24%4
1962
October1st to 15thNight
49%7%16%20%6%
2134
16th to endNight
62%7%12%13%3
2496
November1st to 15thNight
63%6%13%13%3
2533
16th to endNight
67%7%12%9%2
2832
December1st to 15thNight
62%9%17%8%2
2700
16th to endNight
66%5%11%12%3
2862

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
16%16%41%22%3
90
16th to endDay
19%12%44%14%6%2
96
February1st to 15thDay
15%16%50%13%4
90
16th to endDay
16%22%41%14%4
81
March1st to 15thDay
14%22%30%24%7%1
90
16th to endDay
20%12%33%21%9%4
239
April1st to 15thDay
19%13%28%25%11%1
270
16th to endDay
23%13%29%18%11%4
294
May1st to 15thDay
21%18%33%19%6%1
468
16th to endDay
23%12%36%18%5%2
517
June1st to 15thDay
24%11%35%17%6%3
495
16th to endDay
18%13%33%21%9%2
495
July1st to 15thDay
15%8%38%25%9%3
475
16th to endDay
12%10%38%25%9%4
515
August1st to 15thDay
14%8%34%25%11%4
493
16th to endDay
21%8%27%23%12%4
367
September1st to 15thDay
17%8%26%23%19%4
315
16th to endDay
23%14%29%16%13%3
314
October1st to 15thDay
25%18%28%16%8%2
171
16th to endDay
34%19%34%9%1
144
November1st to 15thDay
28%21%34%12%3
135
16th to endDay
27%16%34%16%5%
110
December1st to 15thDay
30%6%38%18%6%
60
16th to endDay
23%13%38%16%7%
67
January1st to 15thNight
20%11%34%26%5%1
900
16th to endNight
18%9%34%27%8%1
960
February1st to 15thNight
14%10%35%27%10%1
880
16th to endNight
12%9%34%30%11%1
660
March1st to 15thNight
17%12%30%28%9%1
720
16th to endNight
15%9%31%28%13%1
621
April1st to 15thNight
18%9%29%32%7%1
539
16th to endNight
22%6%26%29%13%
540
May1st to 15thNight
24%7%27%31%7%
540
16th to endNight
23%6%24%34%9%1
530
June1st to 15thNight
19%7%30%28%13%1
360
16th to endNight
18%6%30%36%6%
360
July1st to 15thNight
17%426%37%13%1
457
16th to endNight
10%425%41%16%1
564
August1st to 15thNight
12%223%38%21%1
539
16th to endNight
18%428%30%16%1
573
September1st to 15thNight
16%5%25%31%17%3
540
16th to endNight
22%9%28%27%10%1
699
October1st to 15thNight
22%12%32%23%7%
720
16th to endNight
29%11%29%20%8%1
768
November1st to 15thNight
28%14%30%19%6%
822
16th to endNight
26%12%29%24%6%1
975
December1st to 15thNight
21%13%33%24%6%1
900
16th to endNight
22%11%27%26%9%1
960
Page generated at 2017-12-01 12:13:46. Version ac04

Copyright 2017 A. Danko


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