Iroquois Falls
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Iroquois Falls clear sky chart from 2005-11-05 to 2017-05-01.

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%
14807
9%
45666
7%
14779
34%
14779
13%
35229

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
21%
896
7%
2685
4%
895
23%
895
7%
2282
January16th to endNight
31%
934
8%
2737
5%
934
34%
934
10%
2256
February1st to 15thNight
35%
704
8%
2287
8%
701
37%
701
11%
1792
February16th to endNight
29%
631
8%
2036
6%
631
32%
631
11%
1628
March1st to 15thNight
29%
720
13%
2033
9%
720
33%
720
14%
1587
March16th to endNight
39%
768
16%
2112
10%
768
43%
768
21%
1515
April1st to 15thNight
30%
638
12%
1743
7%
638
34%
638
18%
1318
April16th to endNight
35%
540
17%
1620
11%
540
41%
540
22%
1132
May1st to 15thNight
37%
380
15%
1376
14%
380
44%
380
18%
937
May16th to endNight
39%
342
9%
1254
10%
342
43%
342
18%
842
June1st to 15thNight
42%
330
6%
1155
5%
330
43%
330
18%
800
June16th to endNight
43%
330
5%
1155
4%
330
44%
330
21%
753
July1st to 15thNight
42%
310
7%
1085
6%
310
44%
310
21%
720
July16th to endNight
50%
348
10%
1151
11%
326
50%
326
21%
746
August1st to 15thNight
50%
491
11%
1472
9%
489
54%
489
22%
1016
August16th to endNight
45%
525
14%
1575
10%
525
48%
525
25%
1041
September1st to 15thNight
39%
638
10%
1655
5%
638
41%
638
23%
1208
September16th to endNight
39%
657
15%
1820
10%
657
42%
657
24%
1261
October1st to 15thNight
28%
660
12%
1980
8%
660
33%
660
15%
1496
October16th to endNight
21%
704
7%
2202
7%
704
23%
704
8%
1848
November1st to 15thNight
18%
700
7%
2452
6%
700
21%
700
8%
2039
November16th to endNight
15%
720
6%
2520
4%
720
18%
720
6%
2150
December1st to 15thNight
17%
881
3%
2681
0%
881
20%
881
6%
2319
December16th to endNight
20%
960
6%
2880
4%
960
21%
960
6%
2543

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
18%11%47%6%35%446%25%
46122
Night
17%13%5%8%7%35%445%23%
45815
TransparencyDay
59%411%17%6%
45789
Night
62%410%15%6%
45667
SeeingDay
24%6%25%26%12%3
5353
Night
25%5%26%29%11%1
14812

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
17%16%8%9%8%35%5%5%6%11%
1253
16th to endDay
13%16%6%10%7%5%6%47%7%13%
1483
February1st to 15thDay
7%15%6%9%9%48%6%6%6%18%
1575
16th to endDay
11%14%9%9%7%47%446%20%
1437
March1st to 15thDay
15%12%49%7%46%5%46%22%
1915
16th to endDay
12%12%47%7%45%5%35%31%
2112
April1st to 15thDay
22%12%46%5%24335%27%
2217
16th to endDay
16%10%47%5%34445%31%
2340
May1st to 15thDay
19%9%47%6%345%46%28%
2256
16th to endDay
23%8%25%5%2445%7%30%
2507
June1st to 15thDay
20%8%35%5%35%5%47%29%
2475
16th to endDay
17%7%36%6%46%5%6%7%30%
2475
July1st to 15thDay
21%6%35%6%35%5%5%8%27%
2475
16th to endDay
17%6%36%6%46%5%6%8%28%
2623
August1st to 15thDay
17%7%37%8%35%5%5%7%26%
2147
16th to endDay
16%8%37%5%35%46%8%29%
2275
September1st to 15thDay
22%8%36%5%33447%30%
1962
16th to endDay
24%7%35%5%23336%33%
1810
October1st to 15thDay
24%13%46%43224427%
1650
16th to endDay
28%20%5%9%6%3432312%
1667
November1st to 15thDay
21%16%8%9%5%24345%18%
1406
16th to endDay
23%20%6%10%8%3423311%
1440
December1st to 15thDay
18%18%9%11%6%34446%12%
1278
16th to endDay
15%20%8%11%8%45%435%11%
1344
January1st to 15thNight
18%16%7%11%8%46%5%45%11%
2685
16th to endNight
11%16%7%11%9%5%6%5%6%6%12%
2737
February1st to 15thNight
7%13%7%10%11%6%7%5%47%17%
2285
16th to endNight
13%18%6%9%7%46%445%17%
2036
March1st to 15thNight
16%12%5%10%8%3434424%
2021
16th to endNight
13%11%46%6%445%5%5%32%
2112
April1st to 15thNight
20%11%5%6%6%3444429%
1743
16th to endNight
20%8%45%424435%36%
1620
May1st to 15thNight
17%8%36%5%345%5%5%32%
1376
16th to endNight
19%7%45%433437%35%
1253
June1st to 15thNight
20%6%26%6%3446%8%29%
1155
16th to endNight
15%7%445%25%347%37%
1155
July1st to 15thNight
16%5%35%6%35%5%6%8%34%
1155
16th to endNight
14%7%24435%6%6%7%37%
1235
August1st to 15thNight
13%6%36%6%35%5%5%8%35%
1482
16th to endNight
15%6%335%345%5%8%37%
1575
September1st to 15thNight
19%8%46%424446%32%
1655
16th to endNight
22%8%25%322446%37%
1820
October1st to 15thNight
21%12%36%5%24446%26%
1980
16th to endNight
24%18%5%9%5%3344415%
2202
November1st to 15thNight
21%17%7%9%7%35%33317%
2452
16th to endNight
24%16%7%11%8%3332314%
2520
December1st to 15thNight
17%19%7%12%8%45%34411%
2681
16th to endNight
19%21%7%9%8%5%6%4448%
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
72%49%11%2
1254
16th to endDay
67%28%12%7%
1483
February1st to 15thDay
64%410%14%5%
1577
16th to endDay
66%28%16%5%
1437
March1st to 15thDay
62%310%13%9%
1926
16th to endDay
55%36%22%10%1
2112
April1st to 15thDay
59%36%18%11%
2217
16th to endDay
54%310%17%12%1
2340
May1st to 15thDay
55%39%18%12%
2256
16th to endDay
52%412%21%7%
2511
June1st to 15thDay
53%5%10%20%10%
2475
16th to endDay
50%5%12%19%9%1
2475
July1st to 15thDay
50%5%15%21%6%
2316
16th to endDay
54%6%14%22%2
2445
August1st to 15thDay
55%5%16%19%2
2133
16th to endDay
50%5%17%19%5%
2275
September1st to 15thDay
54%416%18%5%
1962
16th to endDay
53%413%23%5%
1810
October1st to 15thDay
61%312%17%5%
1650
16th to endDay
79%36%8%2
1667
November1st to 15thDay
69%410%10%4
1406
16th to endDay
80%28%7%1
1440
December1st to 15thDay
73%39%9%2
1278
16th to endDay
75%28%9%3
1344
January1st to 15thNight
73%48%11%1
2685
16th to endNight
70%39%12%4
2737
February1st to 15thNight
65%312%12%5%
2287
16th to endNight
68%28%14%5%
2036
March1st to 15thNight
63%27%14%9%1
2033
16th to endNight
51%49%19%12%2
2112
April1st to 15thNight
57%37%16%12%2
1743
16th to endNight
50%37%19%17%1
1620
May1st to 15thNight
50%49%19%13%1
1376
16th to endNight
49%5%13%18%11%1
1255
June1st to 15thNight
51%410%19%11%1
1155
16th to endNight
45%5%11%24%11%1
1155
July1st to 15thNight
45%6%13%23%9%
1085
16th to endNight
44%6%17%28%3
1151
August1st to 15thNight
46%6%17%25%3
1472
16th to endNight
43%5%19%24%6%
1575
September1st to 15thNight
50%5%16%20%6%
1655
16th to endNight
47%416%28%3
1820
October1st to 15thNight
58%413%17%5%
1980
16th to endNight
72%39%11%3
2202
November1st to 15thNight
72%310%9%3
2452
16th to endNight
76%29%8%2
2520
December1st to 15thNight
76%38%8%1
2681
16th to endNight
79%36%7%2
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
33%5%23%25%10%3
60
16th to endDay
36%321%32%41
83
February1st to 15thDay
18%6%31%35%7%
90
16th to endDay
30%9%35%19%3
81
March1st to 15thDay
23%6%24%33%10%1
216
16th to endDay
20%8%25%30%12%2
288
April1st to 15thDay
22%8%24%31%10%2
270
16th to endDay
21%10%29%20%12%5%
270
May1st to 15thDay
24%6%23%22%17%6%
229
16th to endDay
27%6%26%25%10%4
380
June1st to 15thDay
28%7%21%25%14%2
420
16th to endDay
18%7%24%29%16%3
420
July1st to 15thDay
21%6%27%31%10%3
400
16th to endDay
18%5%25%31%14%4
434
August1st to 15thDay
18%320%30%18%9%
253
16th to endDay
23%5%20%27%15%5%
268
September1st to 15thDay
24%6%20%21%18%8%
255
16th to endDay
29%5%22%27%10%4
254
October1st to 15thDay
30%5%30%22%9%1
255
16th to endDay
31%7%28%24%6%2
183
November1st to 15thDay
30%11%38%15%31
60
16th to endDay
46%8%26%11%6%
60
December1st to 15thDay
26%10%35%18%8%1
60
16th to endDay
28%15%40%9%6%
64
January1st to 15thNight
28%7%28%25%9%1
900
16th to endNight
20%6%22%31%17%2
934
February1st to 15thNight
16%427%38%12%1
704
16th to endNight
23%427%29%14%
631
March1st to 15thNight
23%8%28%30%8%1
720
16th to endNight
18%5%27%36%10%
768
April1st to 15thNight
24%8%27%30%7%
638
16th to endNight
24%5%28%28%10%1
540
May1st to 15thNight
20%330%32%11%
380
16th to endNight
21%5%26%36%9%1
343
June1st to 15thNight
26%5%19%35%12%
330
16th to endNight
18%227%39%11%
330
July1st to 15thNight
17%327%38%12%
310
16th to endNight
19%220%39%16%
348
August1st to 15thNight
19%220%33%21%2
491
16th to endNight
19%325%34%16%
525
September1st to 15thNight
25%423%28%15%2
638
16th to endNight
27%323%27%15%2
657
October1st to 15thNight
29%5%28%26%9%1
660
16th to endNight
36%6%24%22%8%1
704
November1st to 15thNight
31%7%31%22%6%1
700
16th to endNight
34%7%29%22%5%
720
December1st to 15thNight
27%6%30%25%8%
881
16th to endNight
30%5%23%27%11%2
960
Page generated at 2017-05-02 08:43:25. Version ac04

Copyright 2017 A. Danko


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