Wetaskiwin
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wetaskiwin clear sky chart from 2005-11-06 to 2024-10-25.

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 Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(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

By Month

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 Forecast	Data Points
Cloud Cover	Day	10% 9% 3 8% 6% 5% 5% 4 6% 8% 36%	101957
	Night	8% 10% 4 10% 6% 5% 5% 4 6% 8% 33%	96929
Transparency	Day	43% 9% 17% 22% 8% 1	101700
	Night	45% 9% 16% 20% 9% 1	96832
Seeing	Day	12% 7% 25% 31% 19% 6%	15426
	Night	12% 6% 29% 35% 15% 2	24373

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
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	3 13% 4 10% 10% 7% 5% 4 6% 8% 31%	2219
	11th to 20th	Day	4 10% 4 10% 6% 5% 6% 5% 9% 8% 32%	2199
	21st to end	Day	6% 13% 4 10% 5% 5% 5% 4 5% 8% 35%	2646
February	1st to 10th	Day	7% 15% 5% 11% 7% 6% 4 4 7% 8% 27%	1520
	11th to 20th	Day	6% 13% 4 12% 9% 5% 6% 5% 7% 6% 27%	1627
	21st to end	Day	4 11% 6% 11% 8% 8% 8% 6% 7% 7% 25%	1469
March	1st to 10th	Day	4 12% 6% 13% 9% 7% 6% 5% 5% 7% 26%	3138
	11th to 20th	Day	6% 11% 3 7% 4 4 4 4 6% 10% 41%	3474
	21st to end	Day	7% 17% 6% 16% 6% 5% 4 4 5% 7% 23%	3870
April	1st to 10th	Day	9% 12% 4 10% 7% 5% 5% 4 6% 8% 29%	2373
	11th to 20th	Day	12% 12% 4 8% 6% 5% 5% 4 6% 8% 30%	2440
	21st to end	Day	13% 9% 3 7% 6% 6% 5% 5% 6% 9% 31%	2470
May	1st to 10th	Day	16% 11% 4 9% 5% 5% 4 4 5% 6% 30%	4580
	11th to 20th	Day	12% 10% 3 8% 6% 6% 6% 4 7% 8% 30%	4694
	21st to end	Day	14% 8% 3 9% 6% 6% 6% 5% 6% 7% 30%	5161
June	1st to 10th	Day	16% 7% 3 8% 5% 4 5% 4 6% 9% 31%	2850
	11th to 20th	Day	18% 10% 3 9% 6% 6% 5% 4 7% 7% 25%	2850
	21st to end	Day	11% 5% 2 6% 5% 4 6% 5% 7% 10% 38%	2850
July	1st to 10th	Day	8% 5% 2 5% 4 4 4 4 6% 8% 52%	4740
	11th to 20th	Day	9% 4 2 5% 4 4 4 4 7% 8% 48%	4740
	21st to end	Day	10% 5% 2 5% 4 4 4 4 5% 9% 47%	5138
August	1st to 10th	Day	11% 5% 2 6% 5% 4 5% 5% 6% 8% 43%	4480
	11th to 20th	Day	8% 5% 2 5% 5% 4 5% 5% 8% 11% 42%	4120
	21st to end	Day	10% 5% 2 6% 4 5% 5% 4 7% 9% 44%	4521
September	1st to 10th	Day	12% 5% 2 6% 4 4 5% 4 6% 8% 44%	2405
	11th to 20th	Day	15% 8% 2 6% 4 3 4 3 5% 8% 42%	2090
	21st to end	Day	9% 6% 2 6% 4 5% 5% 4 6% 8% 44%	2090
October	1st to 10th	Day	10% 11% 4 8% 5% 5% 5% 3 4 5% 40%	1976
	11th to 20th	Day	9% 8% 4 6% 5% 5% 5% 4 7% 8% 39%	1753
	21st to end	Day	8% 13% 4 7% 5% 5% 6% 5% 6% 7% 33%	1809
November	1st to 10th	Day	9% 15% 5% 9% 7% 6% 6% 4 6% 6% 27%	1488
	11th to 20th	Day	6% 12% 5% 13% 6% 5% 5% 4 6% 7% 31%	1393
	21st to end	Day	5% 10% 5% 13% 7% 6% 5% 5% 6% 7% 31%	1330
December	1st to 10th	Day	6% 13% 5% 12% 8% 7% 7% 5% 6% 6% 26%	1330
	11th to 20th	Day	5% 12% 5% 12% 7% 5% 6% 4 7% 9% 28%	1682
	21st to end	Day	4 9% 3 8% 6% 5% 5% 4 5% 8% 43%	2442
January	1st to 10th	Night	4 11% 5% 13% 8% 7% 6% 5% 6% 7% 27%	4726
	11th to 20th	Night	4 9% 4 11% 10% 7% 5% 5% 7% 6% 33%	4699
	21st to end	Night	6% 13% 4 11% 6% 5% 4 4 6% 8% 33%	5040
February	1st to 10th	Night	5% 11% 5% 13% 7% 7% 6% 4 6% 7% 28%	2660
	11th to 20th	Night	5% 13% 5% 11% 6% 6% 6% 5% 7% 8% 28%	2439
	21st to end	Night	5% 11% 3 11% 7% 5% 6% 5% 7% 7% 32%	1984
March	1st to 10th	Night	3 10% 5% 13% 9% 6% 6% 4 7% 10% 26%	3736
	11th to 20th	Night	6% 9% 3 9% 6% 5% 5% 5% 6% 10% 36%	3504
	21st to end	Night	6% 15% 7% 16% 6% 5% 5% 5% 7% 6% 21%	3781
April	1st to 10th	Night	7% 11% 3 9% 6% 7% 5% 4 8% 8% 31%	1806
	11th to 20th	Night	11% 13% 4 10% 5% 5% 6% 5% 7% 8% 26%	1691
	21st to end	Night	13% 9% 3 7% 5% 4 6% 5% 6% 8% 33%	1710
May	1st to 10th	Night	23% 11% 4 7% 5% 4 5% 4 5% 5% 27%	2376
	11th to 20th	Night	11% 10% 3 9% 7% 6% 7% 5% 7% 9% 27%	2199
	21st to end	Night	15% 9% 3 10% 6% 6% 6% 5% 7% 9% 25%	2414
June	1st to 10th	Night	16% 8% 3 8% 5% 5% 5% 6% 7% 6% 30%	1330
	11th to 20th	Night	16% 11% 4 9% 8% 5% 6% 5% 7% 9% 21%	1330
	21st to end	Night	11% 5% 3 7% 4 5% 6% 7% 8% 9% 36%	1330
July	1st to 10th	Night	9% 5% 2 7% 5% 4 4 4 7% 8% 44%	2220
	11th to 20th	Night	7% 5% 2 6% 6% 5% 5% 4 7% 11% 41%	2220
	21st to end	Night	12% 5% 1 5% 4 3 5% 4 6% 9% 44%	2414
August	1st to 10th	Night	13% 5% 2 6% 4 3 5% 4 7% 9% 41%	2447
	11th to 20th	Night	9% 6% 3 7% 5% 5% 5% 5% 7% 9% 39%	2715
	21st to end	Night	10% 5% 2 7% 5% 4 5% 5% 7% 9% 42%	3146
September	1st to 10th	Night	12% 5% 3 6% 5% 4 5% 4 6% 8% 43%	1772
	11th to 20th	Night	14% 7% 2 5% 4 4 4 3 5% 7% 44%	2090
	21st to end	Night	9% 6% 3 7% 4 4 5% 3 7% 7% 44%	2090
October	1st to 10th	Night	11% 9% 3 7% 4 4 5% 4 6% 8% 39%	2204
	11th to 20th	Night	8% 10% 3 8% 5% 5% 4 4 6% 8% 39%	2425
	21st to end	Night	6% 10% 4 10% 7% 5% 5% 5% 7% 8% 34%	2639
November	1st to 10th	Night	11% 15% 5% 9% 6% 4 4 4 5% 6% 29%	2585
	11th to 20th	Night	7% 13% 5% 12% 6% 5% 5% 4 6% 8% 29%	2783
	21st to end	Night	6% 12% 5% 11% 8% 6% 6% 4 6% 8% 29%	2850
December	1st to 10th	Night	7% 13% 5% 12% 8% 5% 4 4 5% 6% 30%	2850
	11th to 20th	Night	5% 13% 5% 11% 7% 5% 6% 4 7% 9% 28%	3510
	21st to end	Night	3 7% 3 8% 5% 5% 5% 4 6% 9% 43%	5214

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	50% 10% 13% 19% 8% 1	2219
	11th to 20th	Day	45% 7% 12% 14% 20% 2	2220
	21st to end	Day	46% 9% 17% 24% 5%	2646
February	1st to 10th	Day	53% 6% 15% 16% 9% 1	1520
	11th to 20th	Day	53% 10% 14% 16% 8%	1636
	21st to end	Day	52% 9% 14% 17% 8%	1469
March	1st to 10th	Day	53% 8% 15% 15% 8%	3138
	11th to 20th	Day	37% 10% 19% 21% 13%	3475
	21st to end	Day	56% 10% 12% 17% 4	3870
April	1st to 10th	Day	50% 8% 17% 18% 7% 1	2373
	11th to 20th	Day	50% 8% 14% 19% 8%	2440
	21st to end	Day	46% 10% 16% 21% 6% 2	2470
May	1st to 10th	Day	50% 9% 12% 22% 6%	4580
	11th to 20th	Day	46% 12% 14% 21% 8%	4698
	21st to end	Day	46% 13% 16% 17% 8%	5162
June	1st to 10th	Day	47% 9% 15% 21% 7% 1	2850
	11th to 20th	Day	54% 10% 15% 15% 5%	2850
	21st to end	Day	36% 13% 22% 22% 6% 1	2850
July	1st to 10th	Day	30% 8% 17% 29% 15% 2	4666
	11th to 20th	Day	31% 10% 17% 29% 13%	4659
	21st to end	Day	33% 8% 20% 25% 13% 1	4976
August	1st to 10th	Day	37% 10% 17% 33% 3	4462
	11th to 20th	Day	32% 9% 24% 28% 6%	4161
	21st to end	Day	34% 8% 28% 24% 5%	4520
September	1st to 10th	Day	36% 9% 21% 24% 8% 2	2405
	11th to 20th	Day	40% 6% 18% 29% 7%	2090
	21st to end	Day	36% 9% 19% 25% 9% 2	2090
October	1st to 10th	Day	45% 7% 16% 21% 10%	1976
	11th to 20th	Day	40% 9% 18% 22% 10%	1753
	21st to end	Day	48% 10% 12% 22% 8%	1809
November	1st to 10th	Day	55% 9% 14% 15% 6% 1	1488
	11th to 20th	Day	51% 8% 16% 20% 6%	1393
	21st to end	Day	49% 10% 15% 19% 6% 1	1330
December	1st to 10th	Day	56% 7% 12% 15% 8% 2	1330
	11th to 20th	Day	48% 11% 17% 16% 6% 1	1684
	21st to end	Day	38% 6% 11% 25% 17% 3	2442
January	1st to 10th	Night	52% 9% 15% 16% 6% 2	4726
	11th to 20th	Night	48% 7% 13% 15% 14% 2	4740
	21st to end	Night	47% 8% 16% 20% 7%	5040
February	1st to 10th	Night	53% 7% 13% 18% 8% 1	2660
	11th to 20th	Night	49% 10% 14% 16% 10% 1	2440
	21st to end	Night	46% 10% 13% 20% 10% 1	1984
March	1st to 10th	Night	49% 9% 14% 20% 7%	3736
	11th to 20th	Night	40% 10% 21% 18% 11% 1	3504
	21st to end	Night	55% 12% 13% 14% 5%	3781
April	1st to 10th	Night	46% 11% 14% 18% 10% 1	1806
	11th to 20th	Night	52% 8% 12% 18% 8% 2	1691
	21st to end	Night	44% 11% 15% 18% 10% 1	1710
May	1st to 10th	Night	56% 7% 9% 20% 8% 1	2376
	11th to 20th	Night	44% 14% 15% 19% 8% 1	2199
	21st to end	Night	49% 14% 16% 12% 8% 1	2414
June	1st to 10th	Night	49% 11% 14% 18% 8% 1	1330
	11th to 20th	Night	56% 11% 15% 13% 5%	1330
	21st to end	Night	39% 12% 22% 21% 5% 1	1330
July	1st to 10th	Night	36% 9% 17% 22% 15% 2	2185
	11th to 20th	Night	34% 10% 16% 27% 11% 1	2178
	21st to end	Night	34% 9% 21% 26% 10%	2337
August	1st to 10th	Night	37% 11% 18% 31% 2	2440
	11th to 20th	Night	38% 9% 23% 22% 8% 1	2740
	21st to end	Night	36% 9% 21% 29% 5%	3146
September	1st to 10th	Night	37% 9% 16% 24% 12% 2	1772
	11th to 20th	Night	39% 6% 16% 27% 9% 3	2090
	21st to end	Night	36% 10% 14% 24% 13% 3	2090
October	1st to 10th	Night	42% 8% 16% 23% 10% 1	2204
	11th to 20th	Night	41% 8% 15% 26% 9% 1	2425
	21st to end	Night	45% 11% 16% 21% 7% 1	2639
November	1st to 10th	Night	54% 7% 13% 18% 7% 1	2585
	11th to 20th	Night	52% 9% 14% 17% 7% 1	2783
	21st to end	Night	51% 8% 16% 17% 6% 1	2850
December	1st to 10th	Night	53% 7% 11% 18% 9% 2	2850
	11th to 20th	Night	51% 9% 17% 16% 6%	3507
	21st to end	Night	35% 8% 16% 21% 16% 4	5214

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
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	3 9% 30% 33% 19% 5%	180
	11th to 20th	Day	7% 7% 33% 36% 14% 4	180
	21st to end	Day	11% 10% 29% 28% 16% 7%	198
February	1st to 10th	Day	16% 9% 28% 31% 12% 3	180
	11th to 20th	Day	11% 5% 31% 33% 15% 4	252
	21st to end	Day	4 5% 34% 33% 18% 6%	281
March	1st to 10th	Day	10% 9% 30% 30% 18% 3	460
	11th to 20th	Day	7% 6% 33% 33% 15% 6%	460
	21st to end	Day	15% 7% 27% 34% 15% 3	506
April	1st to 10th	Day	10% 14% 32% 30% 11% 3	460
	11th to 20th	Day	15% 9% 23% 31% 16% 6%	452
	21st to end	Day	15% 11% 28% 30% 13% 4	460
May	1st to 10th	Day	15% 10% 22% 33% 15% 6%	599
	11th to 20th	Day	10% 6% 26% 32% 20% 5%	675
	21st to end	Day	16% 4 23% 30% 20% 7%	734
June	1st to 10th	Day	18% 8% 25% 31% 16% 3	680
	11th to 20th	Day	19% 8% 22% 25% 20% 6%	680
	21st to end	Day	12% 5% 20% 30% 23% 10%	680
July	1st to 10th	Day	11% 3 18% 34% 23% 11%	671
	11th to 20th	Day	11% 4 21% 29% 26% 9%	668
	21st to end	Day	9% 6% 17% 31% 27% 11%	739
August	1st to 10th	Day	12% 2 20% 31% 22% 12%	540
	11th to 20th	Day	9% 5% 19% 33% 26% 8%	477
	21st to end	Day	10% 7% 20% 29% 25% 9%	539
September	1st to 10th	Day	14% 9% 24% 27% 20% 6%	490
	11th to 20th	Day	20% 6% 24% 29% 18% 4	490
	21st to end	Day	13% 14% 26% 27% 17% 3	490
October	1st to 10th	Day	15% 7% 28% 28% 16% 5%	376
	11th to 20th	Day	11% 8% 32% 28% 18% 3	300
	21st to end	Day	15% 12% 31% 31% 10% 2	311
November	1st to 10th	Day	15% 9% 29% 30% 14% 3	270
	11th to 20th	Day	11% 7% 32% 35% 12% 2	210
	21st to end	Day	3 6% 38% 34% 12% 6%	180
December	1st to 10th	Day	8% 7% 27% 35% 17% 6%	180
	11th to 20th	Day	9% 10% 31% 32% 16% 3	180
	21st to end	Day	8% 7% 21% 40% 20% 5%	198
January	1st to 10th	Night	9% 9% 32% 35% 14% 1	950
	11th to 20th	Night	10% 8% 35% 33% 12% 2	950
	21st to end	Night	13% 11% 32% 31% 11% 2	936
February	1st to 10th	Night	8% 10% 26% 37% 18% 2	760
	11th to 20th	Night	11% 6% 35% 33% 15%	744
	21st to end	Night	8% 4 28% 36% 20% 4	628
March	1st to 10th	Night	10% 5% 28% 38% 17% 2	760
	11th to 20th	Night	10% 5% 32% 36% 15% 3	760
	21st to end	Night	14% 4 29% 36% 14% 3	836
April	1st to 10th	Night	11% 7% 30% 35% 15% 2	666
	11th to 20th	Night	15% 8% 27% 37% 12% 1	563
	21st to end	Night	15% 7% 27% 35% 14% 1	570
May	1st to 10th	Night	15% 9% 25% 36% 12% 2	432
	11th to 20th	Night	11% 6% 25% 40% 17% 1	374
	21st to end	Night	19% 4 26% 32% 17% 2	411
June	1st to 10th	Night	17% 8% 26% 33% 13% 2	380
	11th to 20th	Night	21% 5% 24% 32% 17% 2	380
	21st to end	Night	12% 4 21% 37% 25% 2	380
July	1st to 10th	Night	14% 1 16% 44% 24% 1	370
	11th to 20th	Night	11% 4 21% 41% 22% 1	368
	21st to end	Night	11% 4 18% 37% 27% 2	416
August	1st to 10th	Night	11% 4 20% 32% 27% 6%	378
	11th to 20th	Night	12% 4 18% 36% 29% 2	504
	21st to end	Night	11% 3 23% 38% 25% 1	627
September	1st to 10th	Night	14% 2 19% 42% 19% 2	613
	11th to 20th	Night	16% 4 21% 40% 17% 1	760
	21st to end	Night	11% 4 31% 41% 11% 2	760
October	1st to 10th	Night	14% 5% 28% 38% 14% 1	760
	11th to 20th	Night	12% 6% 35% 34% 12% 1	760
	21st to end	Night	9% 8% 36% 35% 11% 1	812
November	1st to 10th	Night	18% 6% 32% 33% 10% 1	920
	11th to 20th	Night	13% 8% 36% 30% 10% 2	950
	21st to end	Night	9% 6% 39% 34% 11% 1	950
December	1st to 10th	Night	12% 9% 31% 31% 13% 3	950
	11th to 20th	Night	11% 6% 36% 33% 14% 2	950
	21st to end	Night	9% 4 34% 34% 16% 3	1045

Page generated at 2024-10-22 18:21:02. Version ac07

Copyright © 2024 Attilla Danko.