Swift Current
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Swift Current clear sky chart from 2005-11-06 to 2024-12-09.

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	8% 8% 3 8% 5% 5% 5% 4 6% 8% 41%	105818
	Night	6% 8% 3 8% 5% 5% 5% 4 6% 8% 40%	102610
Transparency	Day	40% 7% 15% 26% 11% 2	105545
	Night	40% 6% 15% 25% 11% 2	102473
Seeing	Day	13% 10% 30% 29% 15% 4	15859
	Night	12% 9% 34% 32% 12% 1	25230

By Month

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
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	6% 10% 4 13% 8% 8% 7% 5% 5% 6% 28%	2219
	11th to 20th	Day	3 7% 3 10% 7% 9% 11% 9% 9% 12% 20%	2220
	21st to end	Day	4 11% 4 7% 5% 5% 6% 5% 6% 7% 40%	2672
February	1st to 10th	Day	7% 14% 6% 14% 8% 5% 7% 4 5% 7% 24%	1703
	11th to 20th	Day	7% 12% 6% 9% 8% 6% 6% 4 7% 7% 29%	1665
	21st to end	Day	4 11% 4 13% 8% 7% 6% 5% 7% 7% 27%	1422
March	1st to 10th	Day	4 11% 5% 12% 9% 8% 5% 4 4 6% 31%	3211
	11th to 20th	Day	5% 11% 6% 11% 5% 4 4 3 6% 9% 37%	3490
	21st to end	Day	5% 14% 8% 16% 6% 5% 5% 4 6% 7% 24%	3943
April	1st to 10th	Day	7% 9% 3 8% 7% 5% 6% 5% 7% 7% 35%	2280
	11th to 20th	Day	11% 13% 5% 9% 6% 5% 5% 5% 6% 7% 28%	2355
	21st to end	Day	14% 11% 3 6% 5% 5% 4 4 6% 8% 35%	2560
May	1st to 10th	Day	18% 14% 3 6% 4 4 4 3 5% 7% 32%	4430
	11th to 20th	Day	8% 6% 3 9% 6% 7% 7% 5% 8% 8% 34%	4388
	21st to end	Day	14% 9% 3 9% 6% 6% 6% 4 7% 7% 30%	5009
June	1st to 10th	Day	15% 8% 3 6% 5% 4 5% 4 7% 8% 35%	2850
	11th to 20th	Day	17% 8% 2 8% 5% 5% 5% 4 7% 7% 33%	2850
	21st to end	Day	9% 4 2 5% 4 5% 5% 5% 7% 10% 44%	2850
July	1st to 10th	Day	5% 5% 2 6% 5% 5% 5% 4 8% 9% 46%	4740
	11th to 20th	Day	5% 3 2 5% 4 4 4 4 7% 10% 53%	4740
	21st to end	Day	3 2 1 3 3 3 4 3 4 8% 64%	4965
August	1st to 10th	Day	7% 4 2 5% 4 4 4 4 6% 8% 53%	4411
	11th to 20th	Day	5% 4 2 4 3 4 4 4 6% 10% 55%	4069
	21st to end	Day	9% 3 2 4 3 3 3 3 5% 8% 58%	4434
September	1st to 10th	Day	11% 5% 2 6% 3 4 5% 4 5% 7% 47%	2280
	11th to 20th	Day	14% 7% 2 6% 3 4 4 4 5% 7% 44%	2280
	21st to end	Day	9% 6% 2 5% 4 3 4 3 6% 7% 51%	2003
October	1st to 10th	Day	8% 6% 2 5% 3 3 4 4 5% 9% 51%	3170
	11th to 20th	Day	5% 6% 2 6% 2 4 4 4 7% 10% 50%	3150
	21st to end	Day	5% 8% 5% 7% 4 4 5% 3 6% 7% 46%	3069
November	1st to 10th	Day	9% 16% 5% 9% 7% 4 4 4 5% 5% 32%	1568
	11th to 20th	Day	5% 12% 4 13% 7% 4 4 5% 5% 7% 34%	1600
	21st to end	Day	8% 11% 5% 11% 7% 5% 6% 4 5% 7% 31%	1600
December	1st to 10th	Day	6% 9% 4 12% 10% 8% 7% 5% 6% 6% 28%	1495
	11th to 20th	Day	3 9% 5% 13% 8% 6% 6% 5% 7% 6% 32%	1685
	21st to end	Day	4 8% 3 8% 5% 5% 4 4 6% 6% 47%	2442
January	1st to 10th	Night	3 9% 4 10% 7% 7% 8% 5% 6% 9% 32%	4726
	11th to 20th	Night	2 7% 4 14% 9% 7% 8% 8% 8% 7% 26%	4740
	21st to end	Night	4 11% 4 9% 6% 5% 6% 5% 6% 7% 37%	4989
February	1st to 10th	Night	4 12% 5% 10% 7% 7% 7% 5% 8% 8% 27%	2494
	11th to 20th	Night	5% 13% 5% 11% 6% 6% 6% 4 8% 8% 27%	2402
	21st to end	Night	4 10% 5% 9% 7% 7% 7% 5% 7% 8% 32%	2032
March	1st to 10th	Night	4 10% 5% 13% 10% 7% 6% 4 6% 7% 29%	3655
	11th to 20th	Night	4 9% 4 11% 6% 4 5% 4 6% 10% 38%	3490
	21st to end	Night	5% 13% 6% 16% 9% 7% 6% 4 6% 7% 22%	3706
April	1st to 10th	Night	7% 9% 2 8% 6% 5% 5% 4 7% 7% 39%	1900
	11th to 20th	Night	10% 14% 4 10% 5% 4 5% 4 4 6% 32%	1771
	21st to end	Night	10% 11% 4 7% 6% 6% 5% 5% 5% 7% 34%	1618
May	1st to 10th	Night	21% 12% 3 5% 3 3 4 3 5% 7% 33%	2540
	11th to 20th	Night	11% 7% 3 7% 5% 4 6% 5% 8% 8% 38%	2517
	21st to end	Night	15% 7% 3 8% 4 4 5% 4 7% 8% 35%	2555
June	1st to 10th	Night	12% 6% 3 6% 4 4 4 4 8% 9% 41%	1330
	11th to 20th	Night	13% 6% 2 7% 4 6% 5% 4 7% 9% 39%	1330
	21st to end	Night	7% 5% 2 5% 4 4 4 4 7% 9% 47%	1330
July	1st to 10th	Night	4 3 2 4 3 4 5% 5% 7% 10% 53%	2220
	11th to 20th	Night	4 3 1 4 3 3 3 3 5% 8% 63%	2220
	21st to end	Night	2 2 1 4 2 3 3 3 5% 8% 68%	2592
August	1st to 10th	Night	8% 4 1 4 3 3 4 3 6% 9% 56%	2528
	11th to 20th	Night	4 3 2 5% 4 4 5% 4 7% 10% 52%	2768
	21st to end	Night	8% 4 2 4 3 3 4 3 5% 7% 55%	3232
September	1st to 10th	Night	9% 4 1 5% 3 4 4 4 5% 6% 55%	1900
	11th to 20th	Night	10% 7% 3 6% 4 4 4 4 5% 8% 46%	1900
	21st to end	Night	8% 6% 2 4 3 3 3 4 5% 9% 53%	2176
October	1st to 10th	Night	9% 7% 2 6% 3 4 4 3 5% 8% 50%	3800
	11th to 20th	Night	6% 4 2 5% 3 3 4 3 6% 9% 54%	3778
	21st to end	Night	6% 9% 2 7% 4 4 4 4 6% 8% 45%	4454
November	1st to 10th	Night	12% 13% 4 8% 6% 5% 4 4 5% 7% 33%	2730
	11th to 20th	Night	5% 11% 3 10% 8% 6% 6% 5% 6% 7% 34%	2800
	21st to end	Night	6% 12% 5% 11% 6% 5% 5% 4 6% 8% 32%	2800
December	1st to 10th	Night	6% 11% 5% 13% 8% 7% 6% 4 6% 7% 27%	2867
	11th to 20th	Night	5% 12% 5% 12% 6% 7% 6% 5% 6% 8% 29%	3506
	21st to end	Night	3 7% 3 7% 5% 3 5% 3 5% 6% 53%	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	53% 9% 14% 18% 6%	2219
	11th to 20th	Day	50% 8% 19% 16% 7% 1	2220
	21st to end	Day	41% 8% 22% 23% 6%	2672
February	1st to 10th	Day	58% 6% 11% 16% 9%	1703
	11th to 20th	Day	51% 8% 15% 14% 11% 1	1674
	21st to end	Day	52% 8% 15% 16% 9% 1	1422
March	1st to 10th	Day	54% 5% 13% 24% 5%	3211
	11th to 20th	Day	43% 8% 21% 21% 6%	3490
	21st to end	Day	58% 9% 14% 13% 5%	3943
April	1st to 10th	Day	45% 8% 15% 22% 10% 1	2280
	11th to 20th	Day	53% 7% 12% 19% 7% 1	2358
	21st to end	Day	47% 6% 12% 26% 8% 1	2560
May	1st to 10th	Day	51% 6% 15% 21% 5% 1	4430
	11th to 20th	Day	40% 9% 15% 25% 10%	4392
	21st to end	Day	48% 10% 16% 20% 6%	5009
June	1st to 10th	Day	44% 8% 16% 22% 10% 1	2850
	11th to 20th	Day	48% 7% 13% 21% 9% 1	2850
	21st to end	Day	33% 10% 19% 28% 10%	2850
July	1st to 10th	Day	32% 7% 21% 21% 17% 2	4666
	11th to 20th	Day	26% 5% 15% 33% 19% 2	4659
	21st to end	Day	19% 4 10% 35% 24% 8%	4808
August	1st to 10th	Day	29% 5% 13% 35% 17% 1	4396
	11th to 20th	Day	25% 5% 17% 36% 15% 1	4109
	21st to end	Day	26% 3 13% 38% 18% 1	4433
September	1st to 10th	Day	35% 6% 13% 25% 17% 5%	2280
	11th to 20th	Day	39% 6% 15% 25% 13% 2	2280
	21st to end	Day	33% 6% 12% 32% 16% 2	2003
October	1st to 10th	Day	32% 3 12% 38% 11% 3	3170
	11th to 20th	Day	29% 4 13% 40% 12% 2	3150
	21st to end	Day	37% 4 13% 36% 9%	3069
November	1st to 10th	Day	53% 6% 13% 20% 8% 1	1568
	11th to 20th	Day	49% 7% 14% 23% 6%	1600
	21st to end	Day	51% 7% 19% 19% 4	1600
December	1st to 10th	Day	55% 8% 16% 16% 5% 1	1495
	11th to 20th	Day	49% 8% 22% 15% 6%	1684
	21st to end	Day	36% 5% 14% 23% 11% 11%	2442
January	1st to 10th	Night	45% 9% 19% 20% 6% 1	4726
	11th to 20th	Night	52% 7% 15% 17% 9% 1	4740
	21st to end	Night	42% 8% 18% 26% 4	4989
February	1st to 10th	Night	51% 7% 14% 17% 10% 1	2494
	11th to 20th	Night	51% 8% 15% 15% 10% 1	2403
	21st to end	Night	46% 7% 13% 23% 10% 1	2032
March	1st to 10th	Night	53% 6% 15% 16% 10%	3655
	11th to 20th	Night	40% 8% 23% 23% 5% 1	3490
	21st to end	Night	60% 9% 13% 13% 5% 1	3706
April	1st to 10th	Night	42% 6% 16% 24% 12% 1	1900
	11th to 20th	Night	52% 5% 12% 18% 11% 3	1771
	21st to end	Night	46% 9% 12% 22% 11% 1	1618
May	1st to 10th	Night	50% 6% 10% 24% 9% 1	2540
	11th to 20th	Night	38% 9% 16% 23% 14% 1	2518
	21st to end	Night	42% 8% 15% 28% 6%	2555
June	1st to 10th	Night	36% 8% 16% 25% 12% 2	1330
	11th to 20th	Night	40% 8% 13% 22% 15% 1	1330
	21st to end	Night	30% 9% 19% 30% 12% 1	1330
July	1st to 10th	Night	24% 7% 23% 31% 16% 1	2185
	11th to 20th	Night	21% 4 12% 38% 22% 3	2178
	21st to end	Night	15% 4 10% 38% 28% 5%	2511
August	1st to 10th	Night	26% 3 15% 35% 19% 1	2520
	11th to 20th	Night	27% 4 15% 36% 16% 2	2794
	21st to end	Night	28% 3 13% 34% 19% 2	3232
September	1st to 10th	Night	29% 5% 11% 28% 19% 8%	1900
	11th to 20th	Night	37% 6% 12% 25% 16% 4	1900
	21st to end	Night	29% 6% 13% 32% 18% 3	2176
October	1st to 10th	Night	34% 4 11% 35% 15%	3800
	11th to 20th	Night	28% 4 14% 38% 16% 1	3778
	21st to end	Night	37% 4 10% 38% 10% 1	4454
November	1st to 10th	Night	50% 7% 13% 20% 9% 1	2730
	11th to 20th	Night	47% 7% 18% 20% 8%	2800
	21st to end	Night	48% 7% 19% 20% 5%	2800
December	1st to 10th	Night	55% 6% 15% 16% 7% 1	2867
	11th to 20th	Night	50% 9% 19% 16% 6% 1	3507
	21st to end	Night	31% 5% 11% 29% 16% 7%	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	11% 15% 33% 26% 14% 1	180
	11th to 20th	Day	7% 14% 33% 30% 12% 3	180
	21st to end	Day	12% 14% 42% 23% 8% 1	265
February	1st to 10th	Day	13% 15% 41% 24% 7%	270
	11th to 20th	Day	9% 10% 44% 25% 10% 2	270
	21st to end	Day	8% 8% 43% 28% 8% 4	225
March	1st to 10th	Day	13% 13% 40% 26% 8% 1	312
	11th to 20th	Day	11% 15% 39% 23% 9% 3	460
	21st to end	Day	14% 11% 32% 28% 11% 4	506
April	1st to 10th	Day	13% 17% 37% 25% 7%	460
	11th to 20th	Day	17% 14% 34% 28% 6% 1	452
	21st to end	Day	19% 11% 26% 32% 11% 1	550
May	1st to 10th	Day	16% 8% 25% 32% 16% 4	653
	11th to 20th	Day	12% 8% 26% 31% 17% 5%	675
	21st to end	Day	19% 10% 19% 26% 22% 4	734
June	1st to 10th	Day	17% 11% 25% 30% 13% 4	680
	11th to 20th	Day	21% 14% 30% 23% 11% 2	680
	21st to end	Day	11% 7% 27% 32% 18% 5%	680
July	1st to 10th	Day	8% 5% 22% 35% 25% 5%	671
	11th to 20th	Day	10% 7% 24% 33% 22% 4	668
	21st to end	Day	5% 8% 21% 34% 24% 8%	739
August	1st to 10th	Day	9% 5% 23% 35% 21% 7%	676
	11th to 20th	Day	11% 4 25% 31% 21% 8%	506
	21st to end	Day	10% 7% 26% 36% 15% 6%	539
September	1st to 10th	Day	14% 8% 31% 28% 15% 3	490
	11th to 20th	Day	17% 7% 26% 34% 14% 1	490
	21st to end	Day	15% 11% 31% 27% 12% 4	390
October	1st to 10th	Day	21% 8% 24% 24% 20% 3	300
	11th to 20th	Day	9% 11% 35% 30% 13% 2	300
	21st to end	Day	13% 15% 40% 22% 9% 1	330
November	1st to 10th	Day	21% 9% 35% 27% 7% 1	300
	11th to 20th	Day	13% 22% 34% 23% 8% 1	300
	21st to end	Day	11% 14% 41% 21% 11% 3	300
December	1st to 10th	Day	8% 11% 50% 21% 7% 3	250
	11th to 20th	Day	9% 21% 44% 18% 6% 1	180
	21st to end	Day	10% 11% 36% 26% 15% 2	198
January	1st to 10th	Night	9% 14% 41% 25% 9% 1	950
	11th to 20th	Night	9% 15% 41% 27% 6% 1	950
	21st to end	Night	9% 16% 39% 26% 9% 1	1045
February	1st to 10th	Night	10% 9% 35% 33% 11% 2	784
	11th to 20th	Night	10% 10% 39% 31% 9% 1	744
	21st to end	Night	8% 8% 32% 34% 16% 3	628
March	1st to 10th	Night	10% 12% 36% 31% 11% 1	760
	11th to 20th	Night	12% 10% 40% 28% 8% 2	760
	21st to end	Night	11% 10% 32% 33% 12% 2	765
April	1st to 10th	Night	11% 8% 36% 34% 10% 1	570
	11th to 20th	Night	16% 9% 36% 30% 8% 1	563
	21st to end	Night	16% 9% 28% 38% 9%	570
May	1st to 10th	Night	16% 5% 28% 33% 17% 2	570
	11th to 20th	Night	13% 6% 25% 38% 17% 2	561
	21st to end	Night	22% 7% 18% 34% 17% 2	501
June	1st to 10th	Night	17% 7% 30% 29% 16% 2	380
	11th to 20th	Night	16% 9% 27% 35% 12%	380
	21st to end	Night	11% 6% 23% 40% 18% 2	380
July	1st to 10th	Night	6% 4 24% 45% 21% 1	370
	11th to 20th	Night	10% 5% 26% 41% 17% 1	368
	21st to end	Night	4 4 27% 43% 19% 2	520
August	1st to 10th	Night	9% 3 27% 40% 19% 3	567
	11th to 20th	Night	7% 3 20% 43% 25% 2	564
	21st to end	Night	12% 3 27% 37% 20% 1	627
September	1st to 10th	Night	11% 4 30% 39% 14% 2	570
	11th to 20th	Night	13% 5% 27% 39% 15% 1	570
	21st to end	Night	12% 4 36% 37% 10% 1	746
October	1st to 10th	Night	17% 8% 29% 32% 13% 1	760
	11th to 20th	Night	13% 8% 35% 31% 11% 3	760
	21st to end	Night	16% 11% 38% 28% 7% 1	984
November	1st to 10th	Night	19% 10% 37% 28% 5% 1	975
	11th to 20th	Night	12% 16% 39% 25% 8% 1	1000
	21st to end	Night	12% 13% 43% 25% 7% 1	1000
December	1st to 10th	Night	11% 11% 39% 27% 10% 2	993
	11th to 20th	Night	10% 15% 40% 26% 8% 1	950
	21st to end	Night	12% 10% 38% 29% 9% 1	1045

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