Minot
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Minot clear sky chart from 2005-11-06 to 2026-08-15.

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	9% 8% 3 8% 5% 5% 5% 4 6% 7% 40%	153017
	Night	7% 8% 3 9% 5% 5% 5% 4 6% 7% 40%	146298
Transparency	Day	41% 6% 14% 25% 12% 1	147607
	Night	42% 6% 14% 24% 12% 1	142732
Seeing	Day	13% 10% 32% 29% 14% 3	18675
	Night	12% 9% 35% 33% 10% 1	28550

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	4 10% 5% 13% 10% 10% 7% 4 7% 6% 26%	4543
	11th to 20th	Day	2 7% 4 15% 10% 9% 12% 8% 9% 7% 18%	4740
	21st to end	Day	5% 8% 4 13% 8% 6% 5% 4 6% 6% 36%	5188
February	1st to 10th	Day	8% 14% 7% 11% 7% 6% 5% 3 6% 6% 27%	1680
	11th to 20th	Day	8% 12% 4 11% 9% 7% 6% 4 5% 7% 26%	1956
	21st to end	Day	6% 11% 5% 13% 8% 6% 6% 4 5% 6% 30%	1730
March	1st to 10th	Day	7% 10% 5% 11% 6% 4 4 3 5% 6% 37%	4600
	11th to 20th	Day	7% 11% 6% 12% 7% 6% 5% 4 6% 8% 27%	4860
	21st to end	Day	12% 17% 6% 13% 6% 4 4 3 4 6% 24%	5908
April	1st to 10th	Day	10% 10% 3 7% 6% 5% 4 4 6% 7% 38%	2520
	11th to 20th	Day	14% 11% 4 9% 5% 5% 5% 4 5% 5% 32%	2619
	21st to end	Day	15% 9% 3 7% 5% 5% 5% 4 5% 6% 35%	2730
May	1st to 10th	Day	11% 6% 2 7% 5% 4 4 4 5% 6% 46%	7939
	11th to 20th	Day	20% 7% 3 6% 4 4 4 3 6% 7% 35%	8191
	21st to end	Day	14% 6% 2 5% 4 4 4 3 5% 7% 46%	9504
June	1st to 10th	Day	12% 6% 2 5% 5% 5% 5% 3 6% 8% 44%	3150
	11th to 20th	Day	11% 5% 2 6% 6% 5% 5% 5% 7% 9% 37%	3150
	21st to end	Day	10% 5% 2 6% 5% 4 6% 5% 7% 9% 42%	3150
July	1st to 10th	Day	7% 5% 2 6% 4 4 6% 5% 7% 10% 44%	8799
	11th to 20th	Day	6% 4 2 5% 4 4 4 4 7% 9% 52%	8250
	21st to end	Day	5% 4 2 6% 4 4 5% 5% 7% 9% 49%	8957
August	1st to 10th	Day	10% 6% 2 7% 4 5% 5% 4 6% 8% 43%	6372
	11th to 20th	Day	9% 5% 2 6% 4 4 4 4 7% 9% 46%	5969
	21st to end	Day	6% 3 2 5% 3 3 4 4 5% 7% 59%	6273
September	1st to 10th	Day	9% 5% 1 5% 3 4 4 3 5% 6% 55%	2400
	11th to 20th	Day	13% 5% 2 6% 3 3 3 3 5% 8% 49%	2250
	21st to end	Day	13% 5% 2 5% 3 3 3 3 4 5% 54%	2200
October	1st to 10th	Day	10% 5% 2 5% 3 3 4 3 5% 6% 55%	3541
	11th to 20th	Day	9% 8% 2 5% 4 3 3 3 5% 8% 51%	2932
	21st to end	Day	9% 10% 3 8% 4 5% 4 4 6% 6% 41%	3190
November	1st to 10th	Day	13% 12% 3 8% 4 4 4 4 5% 5% 37%	1853
	11th to 20th	Day	9% 11% 4 11% 6% 5% 4 3 5% 6% 35%	1755
	21st to end	Day	7% 13% 5% 10% 6% 4 5% 3 6% 7% 34%	1470
December	1st to 10th	Day	5% 14% 6% 14% 7% 5% 6% 4 6% 6% 27%	2360
	11th to 20th	Day	7% 15% 6% 14% 6% 6% 6% 4 5% 6% 24%	2713
	21st to end	Day	6% 9% 5% 13% 7% 4 4 4 5% 5% 38%	3575
January	1st to 10th	Night	4 10% 5% 14% 11% 8% 6% 5% 6% 6% 25%	8364
	11th to 20th	Night	4 9% 4 11% 8% 9% 9% 6% 9% 7% 25%	8250
	21st to end	Night	4 8% 5% 12% 7% 6% 6% 5% 7% 7% 33%	9026
February	1st to 10th	Night	7% 14% 6% 11% 8% 5% 6% 6% 5% 7% 25%	2940
	11th to 20th	Night	7% 11% 4 11% 6% 6% 6% 4 6% 6% 33%	2567
	21st to end	Night	7% 9% 4 9% 6% 4 5% 5% 6% 6% 39%	2076
March	1st to 10th	Night	7% 11% 4 12% 6% 4 4 3 5% 7% 38%	5494
	11th to 20th	Night	7% 10% 4 10% 6% 5% 5% 4 7% 9% 34%	5330
	21st to end	Night	8% 15% 7% 12% 5% 5% 4 4 5% 6% 30%	5276
April	1st to 10th	Night	8% 9% 3 7% 5% 4 4 4 5% 9% 42%	2100
	11th to 20th	Night	12% 11% 3 7% 4 5% 5% 5% 6% 7% 36%	1948
	21st to end	Night	14% 9% 2 8% 4 3 4 4 5% 8% 39%	1890
May	1st to 10th	Night	9% 7% 2 6% 4 4 5% 4 6% 6% 47%	4993
	11th to 20th	Night	18% 7% 2 6% 4 4 4 4 6% 8% 38%	4701
	21st to end	Night	12% 6% 2 6% 4 5% 4 3 5% 7% 46%	4687
June	1st to 10th	Night	11% 3 2 5% 5% 4 5% 5% 7% 8% 45%	1470
	11th to 20th	Night	10% 5% 2 6% 5% 4 5% 4 6% 9% 45%	1470
	21st to end	Night	8% 4 1 5% 4 5% 5% 5% 8% 10% 46%	1470
July	1st to 10th	Night	4 3 1 4 3 4 4 4 7% 11% 53%	4172
	11th to 20th	Night	7% 4 2 5% 3 3 4 4 6% 10% 52%	4740
	21st to end	Night	4 4 2 5% 3 4 5% 4 7% 9% 53%	5152
August	1st to 10th	Night	6% 4 2 5% 3 4 4 4 7% 9% 53%	3660
	11th to 20th	Night	6% 6% 2 5% 4 4 4 3 5% 8% 54%	3968
	21st to end	Night	5% 3 1 3 3 3 3 3 5% 8% 63%	4688
September	1st to 10th	Night	8% 3 2 4 3 3 4 3 5% 6% 59%	2000
	11th to 20th	Night	10% 5% 2 5% 4 4 4 4 5% 7% 50%	2150
	21st to end	Night	13% 6% 1 6% 3 3 3 3 4 7% 52%	2200
October	1st to 10th	Night	8% 5% 2 4 4 3 4 3 5% 7% 56%	3638
	11th to 20th	Night	9% 6% 2 6% 4 4 4 4 6% 8% 47%	4183
	21st to end	Night	8% 8% 3 7% 4 4 5% 3 5% 6% 47%	4610
November	1st to 10th	Night	11% 10% 3 6% 6% 5% 4 4 5% 7% 39%	2665
	11th to 20th	Night	7% 12% 4 10% 6% 6% 4 4 5% 7% 34%	2861
	21st to end	Night	8% 11% 5% 10% 6% 4 4 4 5% 7% 36%	3150
December	1st to 10th	Night	5% 12% 5% 13% 8% 7% 6% 4 5% 7% 29%	5050
	11th to 20th	Night	8% 12% 4 11% 8% 7% 7% 4 5% 6% 27%	5714
	21st to end	Night	6% 9% 4 13% 7% 7% 5% 4 5% 6% 34%	7645

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	55% 6% 15% 16% 7%	4545
	11th to 20th	Day	59% 6% 14% 14% 7%	4740
	21st to end	Day	49% 4 17% 20% 11%	5188
February	1st to 10th	Day	57% 5% 11% 19% 8% 1	1680
	11th to 20th	Day	57% 6% 10% 17% 10%	1966
	21st to end	Day	54% 5% 16% 17% 8% 1	1730
March	1st to 10th	Day	47% 5% 14% 26% 8%	4600
	11th to 20th	Day	52% 8% 14% 20% 6%	4860
	21st to end	Day	60% 7% 11% 16% 6%	5908
April	1st to 10th	Day	44% 7% 13% 23% 12% 2	2520
	11th to 20th	Day	52% 6% 11% 19% 10% 1	2622
	21st to end	Day	48% 6% 13% 23% 9% 1	2730
May	1st to 10th	Day	36% 6% 10% 29% 16% 2	7939
	11th to 20th	Day	46% 5% 9% 22% 15% 2	8195
	21st to end	Day	36% 6% 10% 26% 21% 1	9505
June	1st to 10th	Day	37% 7% 17% 26% 12% 1	3150
	11th to 20th	Day	40% 8% 17% 23% 10% 1	3150
	21st to end	Day	35% 10% 19% 26% 10% 1	3150
July	1st to 10th	Day	32% 8% 22% 28% 8% 1	8726
	11th to 20th	Day	27% 6% 16% 34% 15% 2	8175
	21st to end	Day	28% 8% 17% 29% 15% 2	8759
August	1st to 10th	Day	32% 6% 15% 27% 17% 2	4676
	11th to 20th	Day	33% 7% 18% 33% 9%	4335
	21st to end	Day	26% 5% 16% 37% 14% 1	4522
September	1st to 10th	Day	29% 7% 12% 33% 17% 1	2400
	11th to 20th	Day	34% 6% 16% 27% 15% 1	2250
	21st to end	Day	33% 6% 13% 31% 16% 2	2200
October	1st to 10th	Day	31% 4 12% 30% 20% 4	3541
	11th to 20th	Day	32% 4 14% 38% 12%	2932
	21st to end	Day	42% 5% 9% 29% 14% 1	3190
November	1st to 10th	Day	48% 5% 13% 22% 10% 2	1853
	11th to 20th	Day	49% 5% 17% 19% 8% 1	1755
	21st to end	Day	50% 7% 17% 19% 7% 1	1470
December	1st to 10th	Day	55% 5% 19% 15% 5%	2360
	11th to 20th	Day	60% 6% 15% 15% 3	2710
	21st to end	Day	48% 4 11% 23% 14% 1	3575
January	1st to 10th	Night	57% 6% 12% 17% 8%	8365
	11th to 20th	Night	53% 6% 15% 18% 8%	8250
	21st to end	Night	49% 5% 17% 20% 9%	9026
February	1st to 10th	Night	56% 6% 11% 16% 9% 1	2940
	11th to 20th	Night	49% 6% 12% 21% 11% 1	2567
	21st to end	Night	42% 7% 15% 24% 11% 1	2076
March	1st to 10th	Night	45% 5% 14% 26% 10%	5494
	11th to 20th	Night	43% 8% 17% 24% 7%	5330
	21st to end	Night	53% 8% 14% 19% 6%	5276
April	1st to 10th	Night	40% 6% 12% 24% 15% 2	2100
	11th to 20th	Night	46% 7% 12% 22% 12% 2	1948
	21st to end	Night	42% 6% 13% 25% 13% 2	1890
May	1st to 10th	Night	34% 6% 11% 30% 18% 1	4994
	11th to 20th	Night	43% 6% 11% 22% 17% 2	4702
	21st to end	Night	37% 6% 12% 24% 21% 1	4688
June	1st to 10th	Night	33% 8% 16% 28% 12% 3	1470
	11th to 20th	Night	35% 7% 16% 27% 12% 2	1470
	21st to end	Night	30% 9% 19% 29% 11% 1	1470
July	1st to 10th	Night	24% 9% 24% 34% 8% 1	4137
	11th to 20th	Night	26% 6% 16% 34% 13% 4	4692
	21st to end	Night	26% 8% 21% 25% 19% 2	5038
August	1st to 10th	Night	26% 6% 14% 35% 16% 2	2680
	11th to 20th	Night	29% 7% 18% 33% 12% 1	2878
	21st to end	Night	22% 5% 13% 41% 17% 2	3383
September	1st to 10th	Night	26% 6% 11% 32% 22% 3	2000
	11th to 20th	Night	33% 6% 17% 25% 17% 2	2150
	21st to end	Night	34% 4 10% 32% 18% 2	2200
October	1st to 10th	Night	30% 4 9% 31% 21% 5%	3638
	11th to 20th	Night	35% 4 10% 34% 16% 1	4183
	21st to end	Night	38% 5% 11% 34% 12% 1	4610
November	1st to 10th	Night	44% 7% 12% 22% 13% 2	2665
	11th to 20th	Night	48% 7% 14% 23% 7% 1	2861
	21st to end	Night	48% 7% 17% 20% 8% 1	3150
December	1st to 10th	Night	55% 6% 20% 15% 4	5050
	11th to 20th	Night	57% 5% 19% 14% 4 1	5716
	21st to end	Night	50% 6% 11% 20% 13% 1	7645

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	9% 8% 35% 32% 12% 4	330
	11th to 20th	Day	9% 14% 40% 30% 5% 1	330
	21st to end	Day	12% 13% 37% 26% 11% 2	363
February	1st to 10th	Day	11% 11% 43% 30% 6%	330
	11th to 20th	Day	10% 10% 41% 26% 12% 2	330
	21st to end	Day	8% 13% 36% 33% 10%	273
March	1st to 10th	Day	14% 11% 39% 25% 10% 2	330
	11th to 20th	Day	13% 10% 32% 30% 13% 1	330
	21st to end	Day	16% 12% 35% 27% 8% 2	505
April	1st to 10th	Day	16% 16% 38% 24% 6% 1	540
	11th to 20th	Day	21% 15% 32% 23% 8% 1	660
	21st to end	Day	19% 11% 29% 27% 13% 1	750
May	1st to 10th	Day	14% 12% 27% 31% 14% 1	753
	11th to 20th	Day	21% 11% 25% 27% 11% 4	775
	21st to end	Day	17% 10% 24% 27% 16% 5%	844
June	1st to 10th	Day	13% 10% 32% 25% 16% 4	780
	11th to 20th	Day	12% 13% 36% 25% 13% 2	780
	21st to end	Day	11% 10% 31% 34% 12% 2	780
July	1st to 10th	Day	8% 4 26% 37% 19% 5%	771
	11th to 20th	Day	8% 7% 29% 34% 18% 4	768
	21st to end	Day	6% 4 29% 34% 23% 4	849
August	1st to 10th	Day	9% 6% 26% 33% 20% 5%	776
	11th to 20th	Day	10% 3 24% 35% 23% 5%	736
	21st to end	Day	8% 9% 26% 32% 19% 6%	716
September	1st to 10th	Day	10% 10% 31% 29% 16% 5%	530
	11th to 20th	Day	16% 8% 28% 32% 15% 1	380
	21st to end	Day	15% 11% 33% 25% 13% 2	330
October	1st to 10th	Day	20% 10% 28% 25% 13% 3	330
	11th to 20th	Day	14% 17% 32% 25% 10% 2	330
	21st to end	Day	19% 13% 39% 22% 5% 1	363
November	1st to 10th	Day	21% 12% 33% 22% 11%	330
	11th to 20th	Day	13% 14% 36% 31% 6%	330
	21st to end	Day	12% 13% 35% 29% 10% 1	330
December	1st to 10th	Day	9% 13% 48% 19% 9% 2	330
	11th to 20th	Day	16% 17% 39% 22% 5% 1	330
	21st to end	Day	11% 10% 40% 27% 10% 3	363
January	1st to 10th	Night	10% 11% 42% 28% 8% 1	1050
	11th to 20th	Night	12% 14% 40% 28% 7% 1	1050
	21st to end	Night	10% 12% 40% 29% 9%	1155
February	1st to 10th	Night	13% 12% 37% 29% 8% 1	1050
	11th to 20th	Night	11% 8% 39% 31% 9% 2	892
	21st to end	Night	11% 9% 37% 33% 9% 2	692
March	1st to 10th	Night	13% 10% 35% 32% 8% 2	840
	11th to 20th	Night	10% 10% 38% 31% 9% 1	740
	21st to end	Night	15% 7% 37% 29% 11% 2	693
April	1st to 10th	Night	11% 10% 39% 33% 7%	630
	11th to 20th	Night	17% 11% 36% 30% 6%	623
	21st to end	Night	17% 9% 30% 34% 9%	630
May	1st to 10th	Night	13% 5% 31% 36% 14%	630
	11th to 20th	Night	17% 9% 29% 35% 10%	621
	21st to end	Night	16% 6% 29% 36% 12%	683
June	1st to 10th	Night	13% 7% 34% 32% 13%	630
	11th to 20th	Night	13% 7% 35% 35% 10%	630
	21st to end	Night	9% 5% 31% 42% 13%	630
July	1st to 10th	Night	5% 4 24% 44% 22% 1	615
	11th to 20th	Night	7% 3 32% 44% 14% 1	612
	21st to end	Night	5% 2 27% 49% 16% 1	690
August	1st to 10th	Night	7% 4 23% 49% 17% 1	627
	11th to 20th	Night	7% 4 28% 43% 18% 1	606
	21st to end	Night	6% 3 31% 42% 17% 1	660
September	1st to 10th	Night	10% 5% 30% 37% 17% 2	600
	11th to 20th	Night	12% 5% 34% 39% 10% 1	600
	21st to end	Night	14% 7% 34% 34% 12% 1	600
October	1st to 10th	Night	14% 8% 35% 32% 10%	622
	11th to 20th	Night	16% 13% 30% 32% 8% 1	969
	21st to end	Night	15% 11% 38% 27% 8% 1	1100
November	1st to 10th	Night	16% 13% 35% 29% 7%	1025
	11th to 20th	Night	13% 13% 38% 26% 9% 1	1050
	21st to end	Night	14% 14% 38% 27% 7%	1050
December	1st to 10th	Night	12% 9% 43% 29% 6% 1	1050
	11th to 20th	Night	15% 14% 36% 27% 7% 1	1050
	21st to end	Night	17% 7% 35% 30% 9% 1	1155

Page generated at 2026-08-12 02:37:17. Version ac07

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