Regina
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Regina 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
39%
15473
12%
45578
8%
15435
43%
15435
20%
32047

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
33%
895
8%
2631
5%
895
35%
895
15%
2000
January16th to endNight
24%
960
10%
2688
4%
960
29%
960
13%
2119
February1st to 15thNight
33%
801
9%
2393
5%
801
37%
801
14%
1838
February16th to endNight
38%
632
12%
1974
9%
632
42%
632
16%
1472
March1st to 15thNight
36%
720
13%
2160
8%
720
42%
720
19%
1556
March16th to endNight
36%
654
12%
2004
9%
654
40%
654
14%
1505
April1st to 15thNight
39%
539
16%
1798
12%
539
46%
539
25%
1121
April16th to endNight
40%
540
13%
1566
8%
540
45%
540
21%
1104
May1st to 15thNight
43%
497
12%
1328
6%
497
46%
497
28%
891
May16th to endNight
41%
515
7%
1329
5%
513
42%
513
21%
964
June1st to 15thNight
43%
385
4%
1045
2%
385
45%
385
26%
716
June16th to endNight
49%
330
3%
990
3%
330
50%
330
27%
630
July1st to 15thNight
55%
310
5%
1020
5%
310
58%
310
33%
565
July16th to endNight
62%
522
11%
1304
7%
489
64%
489
46%
731
August1st to 15thNight
62%
494
16%
1312
9%
491
66%
491
42%
765
August16th to endNight
59%
525
22%
1609
17%
525
65%
525
40%
872
September1st to 15thNight
56%
495
18%
1650
18%
495
60%
495
28%
984
September16th to endNight
51%
503
22%
1780
21%
503
58%
503
30%
991
October1st to 15thNight
43%
660
18%
1980
12%
660
48%
660
26%
1294
October16th to endNight
39%
861
16%
2269
9%
861
43%
861
23%
1602
November1st to 15thNight
34%
875
14%
2402
7%
875
39%
875
21%
1730
November16th to endNight
30%
900
13%
2619
7%
900
35%
900
16%
1964
December1st to 15thNight
26%
900
5%
2700
4%
900
28%
900
9%
2252
December16th to endNight
30%
960
8%
3027
5%
960
35%
960
11%
2381

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
12%8%47%6%35%5%5%7%34%
46202
Night
10%9%47%6%35%5%5%7%34%
45736
Cloud CoverDay
12%8%47%6%35%5%5%7%33%
46203
Night
10%9%47%6%35%5%5%7%33%
45738
TransparencyDay
48%7%16%20%6%
45864
Night
48%6%15%20%8%
45578
SeeingDay
15%7%27%29%16%3
5563
Night
13%6%29%34%14%1
15487

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
9%10%5%12%9%46%5%5%8%21%
1304
16th to endDay
6%12%7%13%8%46%5%5%6%22%
1536
February1st to 15thDay
9%11%8%11%8%5%9%6%4419%
1482
16th to endDay
8%13%7%12%11%48%6%5%5%16%
1500
March1st to 15thDay
8%12%8%10%9%46%46%7%20%
1800
16th to endDay
10%10%5%8%6%35%5%6%9%26%
2219
April1st to 15thDay
10%8%47%5%35%5%7%8%33%
2150
16th to endDay
15%11%37%6%25%446%32%
2392
May1st to 15thDay
12%7%36%6%34446%38%
2304
16th to endDay
22%6%35%5%35%45%8%29%
2433
June1st to 15thDay
20%5%36%6%35%45%7%30%
2582
16th to endDay
15%6%25%5%46%5%6%8%34%
2640
July1st to 15thDay
9%324435%5%6%8%45%
2538
16th to endDay
7%3144345%5%9%49%
2460
August1st to 15thDay
9%4245%25%45%7%47%
2310
16th to endDay
10%41442445%7%51%
2238
September1st to 15thDay
13%6%3442335%6%45%
1980
16th to endDay
13%5%23423347%48%
1846
October1st to 15thDay
18%11%36%423346%35%
1650
16th to endDay
13%11%5%6%5%33446%34%
1592
November1st to 15thDay
10%10%5%8%7%3435%6%33%
1455
16th to endDay
12%11%47%8%46%5%5%6%26%
1340
December1st to 15thDay
9%16%8%13%10%48%6%5%412%
1260
16th to endDay
8%13%10%9%10%5%6%7%47%17%
1191
January1st to 15thNight
7%11%6%9%7%37%6%6%7%25%
2631
16th to endNight
6%12%6%11%8%47%6%7%6%22%
2688
February1st to 15thNight
7%11%5%10%8%5%7%6%5%6%24%
2382
16th to endNight
7%10%5%12%8%47%46%7%25%
1974
March1st to 15thNight
8%10%5%9%7%35%5%5%7%30%
2160
16th to endNight
12%11%5%9%7%45%5%46%27%
2001
April1st to 15thNight
9%7%35%435%47%7%40%
1798
16th to endNight
15%8%36%43445%7%34%
1566
May1st to 15thNight
12%8%35%5%25%45%8%38%
1327
16th to endNight
18%5%26%5%35%46%7%34%
1329
June1st to 15thNight
16%5%35%4346%6%6%39%
1045
16th to endNight
13%5%3443335%9%42%
990
July1st to 15thNight
7%31443446%8%50%
1089
16th to endNight
5%21232346%10%57%
1400
August1st to 15thNight
7%2124245%48%56%
1320
16th to endNight
8%413312448%56%
1609
September1st to 15thNight
11%4145%245%5%7%47%
1650
16th to endNight
11%5%23322346%51%
1780
October1st to 15thNight
13%8%35%334338%41%
1980
16th to endNight
9%12%36%5%35%45%6%36%
2269
November1st to 15thNight
13%9%47%5%35%347%35%
2402
16th to endNight
10%12%5%8%7%35%5%47%28%
2619
December1st to 15thNight
10%14%6%12%10%5%7%5%5%5%16%
2700
16th to endNight
7%11%6%12%10%5%6%5%6%7%19%
3027

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
9%10%6%11%9%46%5%6%7%21%
1304
16th to endDay
5%13%6%13%9%36%46%7%21%
1536
February1st to 15thDay
9%12%7%12%8%6%8%6%4418%
1482
16th to endDay
7%13%7%12%10%5%8%6%5%5%16%
1500
March1st to 15thDay
8%13%7%11%8%5%6%46%6%20%
1800
16th to endDay
10%11%5%8%5%35%5%7%9%26%
2220
April1st to 15thDay
9%8%46%5%45%6%6%9%33%
2150
16th to endDay
15%10%46%6%35%447%31%
2392
May1st to 15thDay
12%8%26%6%34447%38%
2304
16th to endDay
21%6%26%5%35%45%8%28%
2433
June1st to 15thDay
19%6%27%6%35%5%5%7%30%
2582
16th to endDay
15%6%25%6%36%5%7%8%34%
2640
July1st to 15thDay
9%3245%445%6%9%44%
2538
16th to endDay
7%3144345%6%8%49%
2460
August1st to 15thDay
9%4245%245%5%8%46%
2310
16th to endDay
10%414424347%50%
2238
September1st to 15thDay
13%6%26%433447%44%
1980
16th to endDay
12%6%23323347%48%
1846
October1st to 15thDay
18%10%45%423345%35%
1650
16th to endDay
12%12%5%7%5%33446%34%
1592
November1st to 15thDay
10%10%5%8%6%4445%6%32%
1455
16th to endDay
11%11%47%8%5%5%5%5%7%25%
1340
December1st to 15thDay
9%15%8%14%11%46%6%5%5%12%
1260
16th to endDay
9%12%9%10%9%5%6%7%47%16%
1191
January1st to 15thNight
7%11%6%9%7%47%6%6%7%24%
2631
16th to endNight
5%12%7%12%7%47%6%7%6%22%
2688
February1st to 15thNight
7%10%6%10%8%6%8%5%5%7%24%
2382
16th to endNight
7%10%5%13%7%5%6%46%7%25%
1974
March1st to 15thNight
8%10%49%7%35%5%6%8%30%
2160
16th to endNight
11%11%5%8%8%45%6%46%27%
2004
April1st to 15thNight
9%8%35%5%25%5%6%7%40%
1798
16th to endNight
15%9%345%345%5%6%34%
1566
May1st to 15thNight
12%7%35%5%2435%8%39%
1327
16th to endNight
18%5%36%5%3447%7%33%
1328
June1st to 15thNight
15%5%26%4336%5%7%38%
1045
16th to endNight
14%6%1333345%9%43%
990
July1st to 15thNight
7%3245%3446%9%49%
1089
16th to endNight
5%2123135%5%10%56%
1400
August1st to 15thNight
7%21342445%8%55%
1320
16th to endNight
8%324322447%56%
1609
September1st to 15thNight
10%4235%35%5%5%7%46%
1650
16th to endNight
11%424423345%52%
1780
October1st to 15thNight
13%9%25%424348%41%
1980
16th to endNight
9%12%36%6%4445%6%36%
2269
November1st to 15thNight
13%9%47%5%34437%35%
2402
16th to endNight
10%12%5%9%7%35%45%7%28%
2619
December1st to 15thNight
10%14%6%12%11%5%7%5%5%416%
2700
16th to endNight
7%11%6%12%10%46%6%6%7%19%
3027

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
59%6%13%16%3
1304
16th to endDay
60%7%15%12%4
1536
February1st to 15thDay
66%7%10%13%2
1482
16th to endDay
67%6%10%10%5%
1500
March1st to 15thDay
61%7%15%12%2
1800
16th to endDay
52%9%17%16%3
2220
April1st to 15thDay
45%9%17%19%7%
2150
16th to endDay
52%5%15%17%7%1
2392
May1st to 15thDay
45%5%12%25%10%
2304
16th to endDay
53%6%13%17%9%
2437
June1st to 15thDay
52%7%14%19%5%
2582
16th to endDay
44%9%19%20%6%
2640
July1st to 15thDay
33%9%21%27%7%
2378
16th to endDay
29%8%21%31%7%
2293
August1st to 15thDay
34%8%24%24%8%1
2294
16th to endDay
31%7%14%33%11%1
2238
September1st to 15thDay
38%5%15%25%13%
1980
16th to endDay
34%5%14%32%11%1
1846
October1st to 15thDay
50%5%14%22%7%
1650
16th to endDay
50%5%18%20%4
1592
November1st to 15thDay
51%7%15%16%7%
1455
16th to endDay
57%8%15%13%5%
1340
December1st to 15thDay
71%8%9%9%1
1260
16th to endDay
65%6%13%12%1
1191
January1st to 15thNight
55%7%15%16%3
2631
16th to endNight
59%7%13%13%5%
2688
February1st to 15thNight
58%5%13%15%5%
2393
16th to endNight
55%6%14%16%6%
1974
March1st to 15thNight
50%6%16%20%4
2160
16th to endNight
57%6%13%17%4
2004
April1st to 15thNight
40%5%14%26%11%1
1798
16th to endNight
47%7%12%20%8%3
1566
May1st to 15thNight
43%313%23%14%1
1328
16th to endNight
48%7%12%17%12%1
1329
June1st to 15thNight
41%8%15%24%9%
1045
16th to endNight
38%6%21%25%7%
990
July1st to 15thNight
29%7%20%32%9%
1020
16th to endNight
21%8%18%37%12%1
1304
August1st to 15thNight
25%8%22%32%9%1
1312
16th to endNight
26%5%13%33%18%2
1609
September1st to 15thNight
34%7%12%26%18%
1650
16th to endNight
33%5%13%30%17%
1780
October1st to 15thNight
42%416%25%9%
1980
16th to endNight
46%6%16%23%6%
2269
November1st to 15thNight
49%6%16%16%9%1
2402
16th to endNight
54%7%16%17%3
2619
December1st to 15thNight
68%6%12%10%1
2700
16th to endNight
61%7%13%13%4
3027

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
7%224%23%37%4
69
16th to endDay
17%8%25%33%14%1
96
February1st to 15thDay
17%5%32%31%12%1
90
16th to endDay
24%425%30%11%2
81
March1st to 15thDay
14%12%44%18%10%
90
16th to endDay
19%12%31%25%9%1
282
April1st to 15thDay
12%17%36%26%5%
269
16th to endDay
16%8%24%31%16%1
408
May1st to 15thDay
17%7%27%30%14%2
395
16th to endDay
21%7%21%27%13%7%
437
June1st to 15thDay
17%9%27%26%15%2
420
16th to endDay
15%5%27%29%17%3
420
July1st to 15thDay
9%5%24%33%22%5%
400
16th to endDay
6%5%27%34%19%5%
445
August1st to 15thDay
9%5%22%36%21%5%
418
16th to endDay
10%7%21%33%22%4
326
September1st to 15thDay
16%8%32%23%18%1
255
16th to endDay
13%8%25%34%11%5%
135
October1st to 15thDay
32%428%21%10%3
90
16th to endDay
18%8%32%26%10%4
96
November1st to 15thDay
13%334%28%16%3
90
16th to endDay
20%8%27%23%18%1
90
December1st to 15thDay
17%228%34%13%3
90
16th to endDay
22%7%43%18%7%1
71
January1st to 15thNight
11%10%29%35%10%1
900
16th to endNight
11%12%38%28%8%
960
February1st to 15thNight
11%5%31%33%15%1
809
16th to endNight
11%5%27%35%16%3
632
March1st to 15thNight
10%7%33%33%13%2
720
16th to endNight
15%8%28%33%13%
654
April1st to 15thNight
13%7%33%32%12%
539
16th to endNight
19%6%27%37%9%
540
May1st to 15thNight
15%7%27%35%13%1
498
16th to endNight
20%5%24%32%15%
515
June1st to 15thNight
18%5%24%38%12%1
385
16th to endNight
15%7%23%37%16%
330
July1st to 15thNight
9%126%39%21%1
310
16th to endNight
5%226%41%23%1
522
August1st to 15thNight
7%222%41%23%2
494
16th to endNight
9%222%39%23%1
525
September1st to 15thNight
12%422%35%23%2
495
16th to endNight
11%5%27%39%14%
503
October1st to 15thNight
18%5%25%33%16%1
660
16th to endNight
17%6%26%37%10%
861
November1st to 15thNight
18%8%30%30%11%1
875
16th to endNight
15%9%34%33%6%1
900
December1st to 15thNight
17%7%30%29%13%2
900
16th to endNight
11%5%31%34%14%2
960
Page generated at 2017-05-02 06:43:29. Version ac04

Copyright 2017 A. Danko


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