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 2017-08-12.

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%
14459
9%
46442
5%
14427
31%
14427
12%
35985

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%
745
4%
2658
2%
741
15%
741
5%
2295
January16th to endNight
17%
768
8%
2688
4%
768
23%
768
6%
2269
February1st to 15thNight
19%
704
6%
2350
3%
701
24%
701
8%
1921
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%
453
8%
1502
8%
451
50%
451
18%
1037
August16th to endNight
44%
525
10%
1575
6%
525
47%
525
21%
1110
September1st to 15thNight
37%
613
11%
1699
5%
613
41%
613
23%
1175
September16th to endNight
35%
657
16%
1815
10%
657
40%
657
26%
1221
October1st to 15thNight
30%
660
16%
1925
8%
660
38%
660
21%
1347
October16th to endNight
24%
704
8%
2274
5%
704
28%
704
12%
1733
November1st to 15thNight
20%
715
13%
2367
6%
715
29%
715
10%
1811
November16th to endNight
19%
750
7%
2591
3%
750
24%
750
7%
2095
December1st to 15thNight
11%
750
3%
2700
0%
750
14%
750
3%
2380
December16th to endNight
13%
800
4%
2880
2%
800
16%
800
3%
2527

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%
47546
Night
19%11%48%7%45%445%24%
46599
TransparencyDay
55%6%14%16%7%
47222
Night
61%5%11%14%6%
46442
SeeingDay
25%8%26%24%11%2
6393
Night
24%11%28%24%9%1
14459

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%7%13%11%6%6%6%4410%
1280
16th to endDay
11%14%410%10%5%10%9%4414%
1536
February1st to 15thDay
8%12%5%9%11%9%9%6%45%16%
1509
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%425%435%6%7%9%35%
2349
16th to endDay
15%5%245%345%6%8%38%
2275
September1st to 15thDay
20%5%23433446%41%
1928
16th to endDay
17%5%245%2325%5%45%
1815
October1st to 15thDay
19%8%245%3445%6%34%
1705
16th to endDay
27%12%25%42435%426%
1595
November1st to 15thDay
21%11%5%8%6%3445%423%
1491
16th to endDay
23%15%5%11%5%33335%18%
1368
December1st to 15thDay
18%15%7%13%10%5%6%33311%
1260
16th to endDay
19%14%7%11%11%5%6%43311%
1344
January1st to 15thNight
15%16%7%10%12%5%6%44311%
2658
16th to endNight
11%15%5%10%11%6%11%6%3313%
2688
February1st to 15thNight
9%11%7%12%12%6%8%44418%
2349
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%5%7%8%32%
1512
16th to endNight
16%6%24435%7%6%8%33%
1575
September1st to 15thNight
17%7%25%5%33445%39%
1699
16th to endNight
21%413323336%43%
1815
October1st to 15thNight
19%7%246%35%45%6%35%
1925
16th to endNight
26%11%36%5%33345%25%
2274
November1st to 15thNight
25%12%47%43333426%
2367
16th to endNight
20%16%6%10%6%3343420%
2591
December1st to 15thNight
19%15%7%12%11%6%5%33310%
2700
16th to endNight
20%14%7%12%10%5%6%43311%
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
75%5%9%6%2
1281
16th to endDay
69%6%10%10%3
1536
February1st to 15thDay
67%6%12%8%2
1512
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%23%20%4
2335
16th to endDay
42%7%24%20%5%
2275
September1st to 15thDay
43%5%18%23%8%
1928
16th to endDay
41%419%25%8%
1815
October1st to 15thDay
50%5%17%18%7%1
1705
16th to endDay
61%5%13%14%4
1595
November1st to 15thDay
61%7%12%14%4
1491
16th to endDay
69%413%10%2
1368
December1st to 15thDay
77%5%8%6%1
1260
16th to endDay
77%5%7%7%1
1344
January1st to 15thNight
76%49%7%1
2658
16th to endNight
73%46%13%2
2688
February1st to 15thNight
67%5%10%11%3
2350
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%9%18%21%4
1502
16th to endNight
44%11%19%18%6%
1575
September1st to 15thNight
45%5%15%23%8%
1699
16th to endNight
43%5%16%23%10%1
1815
October1st to 15thNight
48%413%22%9%
1925
16th to endNight
61%414%15%4
2274
November1st to 15thNight
61%412%15%5%
2367
16th to endNight
67%5%12%10%3
2591
December1st to 15thNight
79%48%6%
2700
16th to endNight
77%5%8%6%1
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
13%20%46%15%5%
60
16th to endDay
20%10%34%20%12%1
64
February1st to 15thDay
16%12%32%27%8%1
170
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
19%326%26%20%3
297
16th to endDay
25%423%25%17%3
268
September1st to 15thDay
23%5%25%25%15%3
255
16th to endDay
20%10%29%23%12%3
254
October1st to 15thDay
23%8%32%18%13%3
235
16th to endDay
38%13%21%16%7%2
240
November1st to 15thDay
32%17%23%19%7%
235
16th to endDay
31%14%24%19%9%1
168
December1st to 15thDay
28%8%30%25%5%3
60
16th to endDay
34%23%23%15%3
64
January1st to 15thNight
23%16%36%17%4
745
16th to endNight
18%19%32%23%6%
768
February1st to 15thNight
14%14%36%24%9%
704
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%33%21%1
453
16th to endNight
17%427%34%15%1
525
September1st to 15thNight
22%5%26%30%13%1
613
16th to endNight
24%5%31%28%8%1
657
October1st to 15thNight
21%9%32%24%9%2
660
16th to endNight
33%12%24%19%8%
704
November1st to 15thNight
29%15%27%20%5%
715
16th to endNight
27%15%29%20%6%
750
December1st to 15thNight
27%19%31%17%4
750
16th to endNight
27%17%26%20%5%1
800
Page generated at 2017-08-13 14:16:17. Version ac04

Copyright 2017 A. Danko


Rimouski Clear Sky Chart | Charts Home