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 2018-02-22.

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%
16579
13%
48816
8%
16541
44%
16541
21%
34025

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%
970
9%
2851
5%
970
36%
970
16%
2150
January16th to endNight
25%
1040
12%
2912
6%
1040
31%
1040
14%
2268
February1st to 15thNight
33%
870
10%
2597
5%
870
38%
870
15%
1959
February16th to endNight
39%
660
13%
2064
10%
660
43%
660
17%
1531
March1st to 15thNight
37%
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
38%
539
16%
1798
12%
539
45%
539
25%
1121
April16th to endNight
39%
540
13%
1566
8%
540
44%
540
21%
1104
May1st to 15thNight
43%
539
12%
1440
6%
539
46%
539
29%
961
May16th to endNight
41%
563
8%
1453
5%
561
42%
561
23%
1037
June1st to 15thNight
43%
420
3%
1140
2%
420
45%
420
27%
767
June16th to endNight
49%
360
3%
1080
3%
360
50%
360
28%
679
July1st to 15thNight
57%
340
5%
1119
5%
340
59%
340
35%
607
July16th to endNight
62%
564
13%
1416
8%
531
65%
531
48%
781
August1st to 15thNight
64%
539
16%
1432
9%
536
67%
536
42%
834
August16th to endNight
59%
573
25%
1757
19%
573
65%
573
41%
942
September1st to 15thNight
55%
540
17%
1800
18%
540
59%
540
30%
1047
September16th to endNight
51%
549
23%
1942
22%
549
58%
549
29%
1093
October1st to 15thNight
43%
720
18%
2160
11%
720
48%
720
26%
1403
October16th to endNight
40%
939
18%
2475
9%
939
44%
939
24%
1726
November1st to 15thNight
33%
950
13%
2608
6%
950
38%
950
20%
1910
November16th to endNight
30%
975
12%
2837
6%
975
35%
975
16%
2113
December1st to 15thNight
27%
975
5%
2925
3%
975
29%
975
10%
2400
December16th to endNight
30%
1040
10%
3280
6%
1040
35%
1040
12%
2531

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
11%8%47%6%35%5%5%7%34%
49453
Night
9%9%47%6%35%5%5%7%34%
48974
Cloud CoverDay
11%8%47%6%35%5%5%7%34%
49454
Night
9%9%47%6%35%5%5%7%34%
48976
TransparencyDay
47%7%15%21%7%
49115
Night
47%6%15%21%8%
48816
SeeingDay
14%7%27%30%16%3
6673
Night
13%6%29%34%14%1
16593

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
8%10%5%12%8%46%6%5%7%21%
1413
16th to endDay
5%12%6%13%8%46%5%5%6%23%
1664
February1st to 15thDay
9%11%8%11%8%5%9%6%45%20%
1609
16th to endDay
7%13%7%12%11%48%6%5%5%17%
1555
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%345%46%39%
2511
16th to endDay
20%6%25%5%35%45%8%30%
2661
June1st to 15thDay
19%5%36%6%35%45%6%32%
2817
16th to endDay
14%6%25%5%35%5%6%8%35%
2880
July1st to 15thDay
9%324435%5%6%8%47%
2769
16th to endDay
6%2144345%5%8%52%
2656
August1st to 15thDay
9%4245%25%45%7%46%
2520
16th to endDay
10%314424347%53%
2442
September1st to 15thDay
12%5%34423346%47%
2160
16th to endDay
13%5%23423447%47%
2014
October1st to 15thDay
17%10%36%423346%36%
1800
16th to endDay
12%11%5%6%5%3345%6%35%
1736
November1st to 15thDay
10%10%5%8%7%4435%6%32%
1579
16th to endDay
11%11%47%7%5%6%5%5%6%28%
1451
December1st to 15thDay
9%16%8%13%10%48%6%5%412%
1365
16th to endDay
8%13%9%10%10%5%6%7%47%17%
1290
January1st to 15thNight
7%11%6%8%8%37%6%6%7%25%
2851
16th to endNight
6%11%6%11%7%47%6%7%6%23%
2912
February1st to 15thNight
7%10%5%9%8%47%6%5%7%25%
2586
16th to endNight
7%10%5%12%8%47%5%6%7%26%
2064
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
11%8%35%5%25%45%8%39%
1439
16th to endNight
16%5%26%5%35%45%7%36%
1453
June1st to 15thNight
15%4344335%6%6%41%
1140
16th to endNight
12%5%3443336%10%43%
1080
July1st to 15thNight
7%31443345%8%52%
1188
16th to endNight
5%21232345%9%59%
1512
August1st to 15thNight
7%2124245%5%8%55%
1440
16th to endNight
7%413312448%57%
1757
September1st to 15thNight
10%4145%2445%7%49%
1800
16th to endNight
10%5%24322446%51%
1942
October1st to 15thNight
13%8%35%334338%42%
2160
16th to endNight
9%11%36%5%35%45%6%37%
2475
November1st to 15thNight
12%9%47%6%35%346%34%
2608
16th to endNight
9%12%48%7%35%5%47%29%
2837
December1st to 15thNight
10%14%6%12%10%46%5%5%5%18%
2925
16th to endNight
7%10%6%12%10%46%5%7%7%20%
3280

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
8%10%5%11%9%46%6%6%7%21%
1413
16th to endDay
5%13%6%13%9%37%46%7%22%
1664
February1st to 15thDay
9%11%6%11%7%6%9%7%45%19%
1609
16th to endDay
7%13%7%12%10%5%8%6%6%6%16%
1555
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%3445%7%38%
2511
16th to endDay
20%6%25%5%35%45%8%30%
2661
June1st to 15thDay
19%6%26%5%35%5%5%7%32%
2817
16th to endDay
14%5%25%6%36%5%7%8%34%
2880
July1st to 15thDay
9%3244445%6%8%46%
2769
16th to endDay
7%2134345%5%8%51%
2656
August1st to 15thDay
10%4245%245%5%8%45%
2520
16th to endDay
9%414424347%52%
2442
September1st to 15thDay
12%6%25%323347%47%
2160
16th to endDay
13%6%23423447%47%
2014
October1st to 15thDay
17%10%35%42335%5%36%
1800
16th to endDay
11%12%5%7%5%33446%35%
1736
November1st to 15thDay
10%10%6%9%7%44346%30%
1579
16th to endDay
11%11%47%8%5%6%5%5%6%27%
1451
December1st to 15thDay
9%15%8%14%10%46%6%5%5%12%
1365
16th to endDay
8%12%8%10%10%5%6%7%5%7%17%
1290
January1st to 15thNight
7%11%5%9%7%47%6%6%7%24%
2851
16th to endNight
5%12%6%11%7%47%5%7%7%23%
2912
February1st to 15thNight
7%10%5%9%8%5%8%5%6%7%25%
2586
16th to endNight
7%9%5%13%7%5%6%5%6%7%25%
2064
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%25%5%2445%8%39%
1439
16th to endNight
17%5%25%5%3447%7%35%
1452
June1st to 15thNight
14%5%25%4236%5%7%40%
1140
16th to endNight
13%6%1332346%9%43%
1080
July1st to 15thNight
6%32443435%9%51%
1188
16th to endNight
5%2122135%5%10%58%
1512
August1st to 15thNight
8%21342445%9%55%
1440
16th to endNight
8%314322447%57%
1757
September1st to 15thNight
10%4235%245%47%49%
1800
16th to endNight
11%5%24423345%51%
1942
October1st to 15thNight
12%8%25%424348%42%
2160
16th to endNight
9%11%36%6%4445%6%37%
2475
November1st to 15thNight
13%9%5%8%6%34436%33%
2608
16th to endNight
9%12%49%7%35%45%7%29%
2837
December1st to 15thNight
10%14%6%11%10%5%6%5%5%418%
2925
16th to endNight
6%11%6%12%10%46%6%7%7%19%
3280

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%4
1413
16th to endDay
59%7%14%12%5%
1664
February1st to 15thDay
64%7%10%14%3
1609
16th to endDay
66%6%10%10%5%
1555
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
44%5%12%26%10%
2511
16th to endDay
51%6%12%18%10%
2665
June1st to 15thDay
50%7%14%20%7%
2817
16th to endDay
43%9%18%21%6%
2880
July1st to 15thDay
32%8%21%28%9%
2609
16th to endDay
27%8%19%31%11%
2489
August1st to 15thDay
35%8%23%25%7%
2504
16th to endDay
30%6%13%35%12%1
2442
September1st to 15thDay
37%5%14%26%14%1
2160
16th to endDay
36%5%14%31%11%1
2014
October1st to 15thDay
49%5%14%23%7%
1800
16th to endDay
48%5%18%21%5%
1736
November1st to 15thDay
53%7%15%16%7%
1579
16th to endDay
56%7%17%14%4
1451
December1st to 15thDay
70%8%9%9%1
1365
16th to endDay
64%6%13%12%2
1290
January1st to 15thNight
54%7%15%17%4
2851
16th to endNight
57%7%14%14%5%
2912
February1st to 15thNight
56%6%14%17%5%
2597
16th to endNight
54%6%14%17%6%
2064
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
42%412%24%14%
1440
16th to endNight
46%7%12%18%13%1
1453
June1st to 15thNight
40%7%15%24%10%1
1140
16th to endNight
37%6%20%26%8%
1080
July1st to 15thNight
28%6%20%32%11%
1119
16th to endNight
20%7%17%36%15%2
1416
August1st to 15thNight
25%7%22%33%10%
1432
16th to endNight
25%5%12%34%19%2
1757
September1st to 15thNight
33%7%11%26%19%1
1800
16th to endNight
33%5%12%30%16%1
1942
October1st to 15thNight
42%416%26%9%
2160
16th to endNight
45%6%16%23%6%
2475
November1st to 15thNight
51%6%16%16%8%1
2608
16th to endNight
53%7%17%16%3
2837
December1st to 15thNight
66%6%13%11%1
2925
16th to endNight
60%6%12%13%6%
3280

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
10%8%24%24%29%2
103
16th to endDay
14%9%31%31%12%
144
February1st to 15thDay
16%338%28%11%
135
16th to endDay
20%6%27%32%13%2
100
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
16%8%28%29%15%2
468
16th to endDay
20%7%21%29%14%7%
517
June1st to 15thDay
16%10%27%26%15%3
495
16th to endDay
15%7%27%30%16%3
495
July1st to 15thDay
8%423%32%24%5%
475
16th to endDay
5%6%28%35%19%4
515
August1st to 15thDay
10%419%35%22%7%
493
16th to endDay
9%6%20%33%24%5%
395
September1st to 15thDay
14%10%31%23%17%1
315
16th to endDay
15%6%23%35%14%4
184
October1st to 15thDay
26%5%27%24%11%3
135
16th to endDay
16%9%35%28%6%2
144
November1st to 15thDay
12%233%33%15%2
135
16th to endDay
19%9%31%25%12%
135
December1st to 15thDay
15%437%29%10%2
135
16th to endDay
16%8%45%20%8%
106
January1st to 15thNight
11%10%30%35%10%1
975
16th to endNight
10%12%37%29%9%
1040
February1st to 15thNight
11%5%33%32%15%1
878
16th to endNight
10%427%37%16%3
660
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%36%13%
540
16th to endNight
19%5%25%33%15%1
563
June1st to 15thNight
17%5%25%38%12%
420
16th to endNight
14%7%23%38%15%
360
July1st to 15thNight
9%125%40%21%1
340
16th to endNight
5%226%41%22%1
564
August1st to 15thNight
7%220%39%25%3
539
16th to endNight
9%222%39%23%1
573
September1st to 15thNight
11%422%35%23%2
540
16th to endNight
11%426%40%14%1
549
October1st to 15thNight
17%5%25%33%16%1
720
16th to endNight
17%7%26%38%10%
939
November1st to 15thNight
17%8%31%30%10%1
950
16th to endNight
14%10%35%32%6%
975
December1st to 15thNight
17%7%30%29%12%2
975
16th to endNight
11%5%32%34%14%2
1040
Page generated at 2018-02-23 10:21:39. Version ac04

Copyright 2018 A. Danko


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