Rimouski
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rimouski clear sky chart from 2005-11-05 to 2018-02-14.

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
26%
15249
9%
48837
5%
15217
31%
15217
12%
37832

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
11%
818
4%
2881
2%
814
15%
814
5%
2508
January16th to endNight
18%
832
8%
2912
4%
832
24%
832
6%
2434
February1st to 15thNight
18%
760
7%
2535
3%
757
24%
757
8%
2071
February16th to endNight
19%
631
6%
1946
2%
631
23%
631
9%
1598
March1st to 15thNight
24%
720
13%
2100
8%
720
29%
720
12%
1650
March16th to endNight
26%
768
16%
2109
7%
768
33%
768
17%
1589
April1st to 15thNight
24%
635
12%
1713
5%
635
28%
635
14%
1358
April16th to endNight
29%
540
15%
1620
9%
540
36%
540
18%
1163
May1st to 15thNight
31%
510
9%
1563
7%
510
34%
510
14%
1180
May16th to endNight
27%
375
9%
1310
5%
374
35%
374
12%
964
June1st to 15thNight
42%
360
4%
1260
4%
360
43%
360
15%
901
June16th to endNight
41%
360
5%
1260
4%
360
43%
360
15%
904
July1st to 15thNight
43%
340
6%
1190
6%
340
46%
340
17%
822
July16th to endNight
47%
376
7%
1347
8%
354
50%
354
16%
935
August1st to 15thNight
48%
464
8%
1535
8%
462
51%
462
19%
1063
August16th to endNight
44%
573
12%
1719
7%
573
47%
573
21%
1206
September1st to 15thNight
38%
669
11%
1854
6%
669
41%
669
24%
1279
September16th to endNight
35%
717
17%
1980
11%
717
41%
717
26%
1340
October1st to 15thNight
31%
720
16%
2100
8%
720
39%
720
21%
1451
October16th to endNight
24%
768
9%
2481
5%
768
29%
768
13%
1876
November1st to 15thNight
22%
783
13%
2570
6%
783
30%
783
11%
1946
November16th to endNight
18%
825
7%
2807
3%
825
23%
825
7%
2285
December1st to 15thNight
11%
825
3%
2925
0%
825
15%
825
3%
2569
December16th to endNight
13%
880
4%
3120
2%
880
17%
880
3%
2740

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%9%36%6%35%5%5%6%29%
49255
Night
19%11%48%7%45%445%24%
48994
TransparencyDay
55%6%14%16%7%
48931
Night
61%5%11%14%6%
48837
SeeingDay
25%9%26%24%11%2
6935
Night
24%11%28%24%9%1
15249

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
13%16%6%13%11%5%7%6%449%
1387
16th to endDay
11%13%410%10%5%9%9%4415%
1664
February1st to 15thDay
8%12%5%9%11%9%9%6%5%5%17%
1625
16th to endDay
16%13%7%9%7%46%5%4420%
1524
March1st to 15thDay
18%11%5%6%6%5%6%5%5%5%23%
1850
16th to endDay
14%15%5%7%5%34445%29%
2115
April1st to 15thDay
21%12%45%5%24446%27%
2235
16th to endDay
22%8%35%423345%35%
2340
May1st to 15thDay
21%7%35%5%245%45%34%
2397
16th to endDay
22%8%35%42445%7%30%
2805
June1st to 15thDay
20%6%35%5%25%5%6%7%30%
2700
16th to endDay
22%6%26%5%35%5%6%7%29%
2700
July1st to 15thDay
16%6%26%5%35%6%6%7%34%
2700
16th to endDay
16%5%25%5%345%6%7%37%
2725
August1st to 15thDay
15%5%25%5%35%6%7%9%35%
2401
16th to endDay
15%5%25%5%345%6%8%38%
2483
September1st to 15thDay
21%5%23433446%41%
2103
16th to endDay
17%5%245%2325%5%45%
1980
October1st to 15thDay
18%8%245%3445%6%35%
1860
16th to endDay
26%12%2443445%427%
1740
November1st to 15thDay
22%11%5%7%6%3445%424%
1618
16th to endDay
23%16%5%10%5%33335%18%
1482
December1st to 15thDay
18%16%6%13%10%5%6%33411%
1365
16th to endDay
18%14%6%11%11%5%6%44311%
1456
January1st to 15thNight
15%16%7%11%12%5%6%44311%
2881
16th to endNight
10%14%5%10%12%6%11%6%3414%
2912
February1st to 15thNight
9%11%7%12%12%6%8%43418%
2534
16th to endNight
16%17%6%9%9%4434319%
1946
March1st to 15thNight
17%14%5%7%7%46%43424%
2087
16th to endNight
15%14%5%6%5%43245%31%
2109
April1st to 15thNight
24%12%47%6%3443425%
1713
16th to endNight
27%7%35%223345%34%
1620
May1st to 15thNight
25%8%36%5%25%435%27%
1563
16th to endNight
24%9%25%5%36%445%27%
1308
June1st to 15thNight
18%8%27%5%436%5%6%29%
1260
16th to endNight
22%6%35%5%45%45%7%28%
1260
July1st to 15thNight
18%6%36%5%45%5%7%8%29%
1260
16th to endNight
14%6%36%5%37%6%7%8%31%
1440
August1st to 15thNight
16%5%25%6%36%6%7%8%32%
1545
16th to endNight
16%6%24435%7%6%8%33%
1719
September1st to 15thNight
18%7%25%5%33445%39%
1854
16th to endNight
21%5%24423336%43%
1980
October1st to 15thNight
19%7%245%35%45%6%37%
2100
16th to endNight
26%11%36%5%33346%25%
2481
November1st to 15thNight
24%12%46%43433427%
2570
16th to endNight
20%16%6%10%6%3343419%
2807
December1st to 15thNight
20%15%7%12%11%5%5%33311%
2925
16th to endNight
19%14%7%12%10%6%6%43311%
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
75%6%9%6%2
1388
16th to endDay
68%6%10%11%3
1664
February1st to 15thDay
66%6%12%9%2
1628
16th to endDay
66%311%12%5%
1524
March1st to 15thDay
61%5%10%15%7%
1860
16th to endDay
57%410%17%10%
2115
April1st to 15thDay
57%311%16%9%1
2235
16th to endDay
51%310%19%13%1
2340
May1st to 15thDay
51%5%10%20%10%1
2397
16th to endDay
53%7%11%19%8%
2809
June1st to 15thDay
51%6%12%15%11%1
2700
16th to endDay
53%6%14%16%8%
2700
July1st to 15thDay
46%7%18%20%7%
2541
16th to endDay
46%8%17%19%8%
2556
August1st to 15thDay
43%8%22%20%4
2387
16th to endDay
42%6%23%21%5%
2483
September1st to 15thDay
43%5%17%23%8%
2103
16th to endDay
41%5%18%24%9%
1980
October1st to 15thDay
48%5%17%19%8%1
1860
16th to endDay
60%5%13%15%4
1740
November1st to 15thDay
61%6%13%14%3
1618
16th to endDay
68%413%10%2
1482
December1st to 15thDay
77%5%8%6%1
1365
16th to endDay
77%5%8%7%2
1456
January1st to 15thNight
76%5%8%7%1
2881
16th to endNight
72%46%13%2
2912
February1st to 15thNight
67%5%10%11%3
2535
16th to endNight
68%49%12%4
1946
March1st to 15thNight
63%47%15%8%
2100
16th to endNight
56%38%19%10%1
2109
April1st to 15thNight
62%47%11%12%1
1713
16th to endNight
53%37%18%15%1
1620
May1st to 15thNight
58%47%16%9%1
1563
16th to endNight
58%5%9%16%9%1
1310
June1st to 15thNight
54%5%11%17%9%1
1260
16th to endNight
53%6%11%17%10%
1260
July1st to 15thNight
50%6%16%19%6%
1190
16th to endNight
49%8%15%17%8%
1347
August1st to 15thNight
45%10%17%21%4
1535
16th to endNight
43%10%19%19%6%
1719
September1st to 15thNight
45%5%15%23%8%
1854
16th to endNight
43%5%16%23%9%
1980
October1st to 15thNight
47%413%23%9%
2100
16th to endNight
60%415%15%4
2481
November1st to 15thNight
60%412%16%5%
2570
16th to endNight
68%5%11%10%3
2807
December1st to 15thNight
78%48%6%1
2925
16th to endNight
77%5%8%6%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
14%17%42%22%3
90
16th to endDay
18%14%37%19%8%1
96
February1st to 15thDay
14%15%34%27%7%
206
16th to endDay
28%11%26%20%8%3
230
March1st to 15thDay
28%13%26%20%9%1
270
16th to endDay
20%14%29%19%13%2
288
April1st to 15thDay
29%10%24%25%7%2
270
16th to endDay
26%9%31%18%8%5%
270
May1st to 15thDay
30%5%26%25%9%2
315
16th to endDay
30%12%24%22%7%2
519
June1st to 15thDay
27%6%23%25%15%2
495
16th to endDay
27%426%28%11%2
495
July1st to 15thDay
22%425%30%14%2
475
16th to endDay
18%322%36%16%1
396
August1st to 15thDay
18%325%28%19%3
313
16th to endDay
24%6%21%25%16%5%
332
September1st to 15thDay
24%5%25%26%15%3
315
16th to endDay
20%8%27%25%14%2
314
October1st to 15thDay
22%9%32%20%11%2
285
16th to endDay
37%14%20%15%9%1
288
November1st to 15thDay
31%17%23%19%8%
280
16th to endDay
33%13%26%18%7%
207
December1st to 15thDay
28%8%30%23%6%2
90
16th to endDay
27%25%23%20%3
96
January1st to 15thNight
24%16%36%18%4
818
16th to endNight
17%18%32%24%5%
832
February1st to 15thNight
14%14%37%24%8%
760
16th to endNight
25%10%31%22%7%1
631
March1st to 15thNight
24%14%27%23%9%
720
16th to endNight
22%15%27%23%8%1
768
April1st to 15thNight
31%12%26%19%9%1
635
16th to endNight
32%8%25%22%10%
540
May1st to 15thNight
28%6%23%29%11%
510
16th to endNight
29%8%26%24%10%
375
June1st to 15thNight
23%420%33%16%1
360
16th to endNight
25%418%36%13%1
360
July1st to 15thNight
18%5%23%34%14%2
340
16th to endNight
17%322%37%17%1
376
August1st to 15thNight
18%321%32%21%1
464
16th to endNight
18%426%33%14%2
573
September1st to 15thNight
22%5%25%30%14%1
669
16th to endNight
24%5%29%28%9%1
717
October1st to 15thNight
21%8%33%25%9%1
720
16th to endNight
32%12%25%20%9%
768
November1st to 15thNight
29%15%26%21%5%1
783
16th to endNight
28%14%30%19%6%
825
December1st to 15thNight
27%18%31%17%4
825
16th to endNight
26%17%27%20%6%1
880
Page generated at 2018-02-15 10:58:52. Version ac04

Copyright 2018 A. Danko


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