Red Deer
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Red Deer 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
41%
15858
11%
48866
8%
15832
44%
15832
19%
34357

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
10%
2910
7%
970
36%
970
14%
2212
January16th to endNight
35%
933
16%
3013
9%
933
43%
933
16%
2135
February1st to 15thNight
37%
754
12%
2620
11%
753
42%
753
15%
1871
February16th to endNight
40%
632
11%
1998
11%
632
43%
632
17%
1438
March1st to 15thNight
35%
720
13%
2116
7%
720
41%
720
19%
1541
March16th to endNight
35%
768
10%
2085
4%
767
38%
767
17%
1587
April1st to 15thNight
34%
614
10%
1694
4%
614
38%
614
17%
1280
April16th to endNight
39%
540
11%
1620
10%
540
41%
540
20%
1129
May1st to 15thNight
39%
398
9%
1359
8%
398
42%
398
18%
947
May16th to endNight
40%
374
3%
1309
1%
374
41%
374
16%
930
June1st to 15thNight
41%
360
0%
1260
0%
360
41%
360
14%
933
June16th to endNight
49%
360
0%
1260
0%
360
49%
360
18%
856
July1st to 15thNight
62%
340
0%
1190
0%
340
62%
340
23%
751
July16th to endNight
65%
376
5%
1239
5%
354
66%
354
26%
754
August1st to 15thNight
63%
384
7%
1455
9%
382
64%
382
21%
895
August16th to endNight
61%
573
14%
1719
13%
573
63%
573
31%
1065
September1st to 15thNight
55%
645
16%
1791
12%
645
56%
645
29%
1152
September16th to endNight
52%
716
18%
1980
12%
716
56%
716
34%
1241
October1st to 15thNight
44%
720
13%
2136
8%
720
48%
720
22%
1483
October16th to endNight
41%
768
16%
2496
11%
768
49%
768
21%
1674
November1st to 15thNight
33%
923
15%
2646
10%
923
38%
923
20%
1910
November16th to endNight
29%
975
11%
2925
6%
975
34%
975
16%
2145
December1st to 15thNight
34%
975
11%
2925
8%
975
37%
975
16%
2189
December16th to endNight
35%
1040
15%
3120
9%
1040
40%
1040
19%
2239

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%9%47%6%35%5%6%8%32%
49251
Night
8%10%48%6%35%5%6%8%31%
49018
TransparencyDay
48%7%17%19%6%
48902
Night
48%7%15%19%7%1
48872
SeeingDay
15%6%24%30%18%4
6442
Night
13%5%27%35%16%1
15871

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%12%5%8%8%45%5%7%8%25%
1358
16th to endDay
7%13%48%6%35%6%5%8%29%
1576
February1st to 15thDay
8%12%6%8%6%45%5%5%8%27%
1540
16th to endDay
6%11%7%11%9%47%6%5%6%23%
1476
March1st to 15thDay
7%11%5%9%8%36%46%8%26%
1844
16th to endDay
10%13%6%8%6%45%47%8%24%
2132
April1st to 15thDay
12%11%5%9%7%36%5%6%7%24%
2254
16th to endDay
14%11%37%6%35%46%8%27%
2340
May1st to 15thDay
9%9%36%6%36%5%6%9%33%
2592
16th to endDay
19%7%36%5%35%5%6%7%29%
2802
June1st to 15thDay
17%7%37%6%46%5%6%7%26%
2700
16th to endDay
14%5%26%5%36%6%7%8%31%
2700
July1st to 15thDay
11%5%25%5%35%6%7%9%37%
2700
16th to endDay
9%4245%46%6%6%8%42%
2846
August1st to 15thDay
12%425%435%6%7%9%38%
2496
16th to endDay
9%4135%35%5%6%9%43%
2483
September1st to 15thDay
15%7%2442345%7%41%
2166
16th to endDay
10%6%25%4335%7%9%42%
1980
October1st to 15thDay
14%9%37%5%345%5%6%34%
1822
16th to endDay
10%10%46%5%35%6%5%6%34%
1728
November1st to 15thDay
6%14%6%9%7%45%46%6%27%
1530
16th to endDay
5%12%5%10%8%45%45%7%29%
1365
December1st to 15thDay
6%15%6%10%9%45%5%46%25%
1365
16th to endDay
411%6%11%9%37%5%6%9%24%
1456
January1st to 15thNight
6%12%6%11%8%5%6%6%6%8%23%
2910
16th to endNight
6%13%5%8%6%36%6%5%7%29%
3013
February1st to 15thNight
7%11%6%10%8%45%45%7%29%
2612
16th to endNight
8%10%5%10%7%36%5%5%8%28%
1998
March1st to 15thNight
6%9%5%9%7%36%7%7%9%27%
2116
16th to endNight
8%11%8%10%6%35%5%7%8%23%
2085
April1st to 15thNight
10%12%48%8%35%6%7%7%25%
1694
16th to endNight
11%11%47%5%35%5%48%31%
1620
May1st to 15thNight
12%10%46%6%45%7%5%6%31%
1358
16th to endNight
18%7%36%6%36%5%6%8%26%
1309
June1st to 15thNight
17%9%36%5%36%6%6%8%25%
1260
16th to endNight
11%5%36%7%46%6%7%8%32%
1260
July1st to 15thNight
8%425%5%35%5%7%12%38%
1260
16th to endNight
7%4245%35%5%8%9%43%
1323
August1st to 15thNight
11%4145%36%5%6%9%39%
1462
16th to endNight
8%415%435%6%7%10%42%
1719
September1st to 15thNight
12%5%24425%5%6%6%43%
1791
16th to endNight
10%6%25%424449%46%
1980
October1st to 15thNight
10%9%37%5%45%45%7%34%
2136
16th to endNight
8%9%36%6%35%5%6%8%34%
2496
November1st to 15thNight
8%11%5%9%7%45%6%5%7%29%
2646
16th to endNight
6%12%6%10%8%35%45%7%28%
2925
December1st to 15thNight
6%12%6%10%8%35%5%5%7%27%
2925
16th to endNight
412%5%10%8%45%5%6%8%27%
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
53%6%14%16%6%1
1358
16th to endDay
51%6%14%16%9%1
1576
February1st to 15thDay
53%5%15%17%7%1
1540
16th to endDay
57%5%11%19%5%
1476
March1st to 15thDay
53%7%16%15%6%
1844
16th to endDay
55%7%15%16%4
2133
April1st to 15thDay
56%7%14%15%5%
2254
16th to endDay
52%7%15%17%6%1
2340
May1st to 15thDay
45%7%16%21%8%
2592
16th to endDay
51%7%16%17%6%
2807
June1st to 15thDay
54%7%15%18%3
2700
16th to endDay
46%10%19%21%2
2700
July1st to 15thDay
40%9%25%21%3
2541
16th to endDay
37%9%24%24%4
2667
August1st to 15thDay
38%11%26%19%4
2479
16th to endDay
32%8%25%24%7%1
2483
September1st to 15thDay
41%5%18%22%9%2
2166
16th to endDay
36%8%16%27%8%2
1980
October1st to 15thDay
48%5%16%20%8%
1822
16th to endDay
47%6%14%23%7%
1728
November1st to 15thDay
54%7%13%16%6%1
1530
16th to endDay
52%7%17%14%6%1
1365
December1st to 15thDay
60%6%11%16%4
1365
16th to endDay
52%6%15%16%7%1
1456
January1st to 15thNight
56%7%14%14%5%2
2910
16th to endNight
52%5%12%17%9%2
3013
February1st to 15thNight
53%6%12%19%7%
2623
16th to endNight
53%5%13%15%11%1
1998
March1st to 15thNight
50%8%16%19%5%
2116
16th to endNight
55%6%14%17%5%
2088
April1st to 15thNight
53%7%15%16%6%
1694
16th to endNight
48%6%15%21%6%1
1620
May1st to 15thNight
49%6%12%20%9%
1359
16th to endNight
52%6%15%16%8%
1309
June1st to 15thNight
54%8%13%17%4
1260
16th to endNight
45%9%19%19%5%1
1260
July1st to 15thNight
36%11%25%22%3
1190
16th to endNight
32%11%22%26%5%
1239
August1st to 15thNight
37%11%24%21%5%
1455
16th to endNight
32%9%20%27%9%1
1719
September1st to 15thNight
37%7%14%25%11%3
1791
16th to endNight
35%5%17%25%12%3
1980
October1st to 15thNight
47%6%16%19%8%
2136
16th to endNight
44%7%19%22%6%
2496
November1st to 15thNight
50%6%13%20%7%1
2646
16th to endNight
54%6%15%14%6%2
2925
December1st to 15thNight
55%6%12%19%5%
2925
16th to endNight
51%5%13%21%7%
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
12%423%32%17%10%
90
16th to endDay
36%31%25%25%9%
96
February1st to 15thDay
20%5%23%29%17%4
95
16th to endDay
13%428%31%19%2
135
March1st to 15thDay
11%9%42%26%8%1
270
16th to endDay
12%6%39%25%15%1
288
April1st to 15thDay
16%13%31%29%8%1
269
16th to endDay
23%7%26%28%11%2
270
May1st to 15thDay
13%9%21%32%17%4
408
16th to endDay
20%419%30%20%5%
517
June1st to 15thDay
20%7%20%33%15%3
495
16th to endDay
16%422%30%20%5%
495
July1st to 15thDay
14%215%34%24%6%
475
16th to endDay
10%419%34%26%5%
515
August1st to 15thDay
12%415%33%23%9%
315
16th to endDay
10%5%23%31%24%5%
332
September1st to 15thDay
23%424%23%20%3
315
16th to endDay
9%9%27%30%15%6%
315
October1st to 15thDay
24%5%26%24%17%2
195
16th to endDay
15%11%24%34%11%2
144
November1st to 15thDay
15%229%35%13%3
132
16th to endDay
10%6%37%24%13%7%
90
December1st to 15thDay
7%7%34%23%23%3
90
16th to endDay
9%429%37%14%5%
96
January1st to 15thNight
13%7%31%33%13%1
975
16th to endNight
12%7%31%33%12%1
933
February1st to 15thNight
11%7%25%35%17%1
760
16th to endNight
12%425%35%18%2
632
March1st to 15thNight
11%336%35%12%1
720
16th to endNight
13%5%28%38%13%1
768
April1st to 15thNight
16%7%28%33%13%
614
16th to endNight
17%7%25%37%11%
540
May1st to 15thNight
15%6%23%36%15%1
399
16th to endNight
22%322%30%17%2
375
June1st to 15thNight
21%425%31%14%2
360
16th to endNight
14%322%37%21%1
360
July1st to 15thNight
12%17%47%22%
340
16th to endNight
8%313%45%26%1
376
August1st to 15thNight
13%313%31%34%4
384
16th to endNight
9%318%41%26%
573
September1st to 15thNight
13%220%39%21%1
645
16th to endNight
13%324%36%18%3
716
October1st to 15thNight
16%426%34%15%2
720
16th to endNight
13%5%30%37%12%
768
November1st to 15thNight
13%8%34%31%10%2
923
16th to endNight
13%6%37%29%11%2
975
December1st to 15thNight
12%7%29%31%15%2
975
16th to endNight
10%334%33%15%2
1040
Page generated at 2018-02-15 08:58:45. Version ac04

Copyright 2018 A. Danko


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