North Platte
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the North Platte clear sky chart from 2005-11-06 to 2026-08-30.

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% 5% 2 5% 3 3 4 3 5% 7% 54%	152291
	Night	7% 6% 2 6% 4 4 4 4 5% 7% 51%	147389
Transparency	Day	29% 5% 12% 27% 21% 5%	147131
	Night	32% 5% 13% 26% 20% 4	143561
Seeing	Day	10% 8% 31% 32% 15% 3	18321
	Night	10% 8% 37% 37% 8%	28142

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	8% 10% 3 6% 4 3 4 3 4 5% 51%	4720
	11th to 20th	Day	4 8% 3 7% 4 4 4 3 6% 5% 51%	4740
	21st to end	Day	4 7% 3 9% 5% 5% 5% 3 5% 7% 47%	5333
February	1st to 10th	Day	7% 9% 4 9% 5% 4 4 4 5% 7% 43%	2027
	11th to 20th	Day	5% 9% 3 7% 4 4 4 4 5% 7% 47%	2049
	21st to end	Day	6% 7% 3 5% 3 3 3 3 4 6% 58%	1730
March	1st to 10th	Day	11% 6% 2 4 2 3 3 2 5% 5% 57%	4600
	11th to 20th	Day	8% 5% 2 4 3 3 3 3 4 6% 58%	4954
	21st to end	Day	9% 8% 2 6% 4 3 4 4 6% 8% 48%	5741
April	1st to 10th	Day	10% 6% 2 4 3 3 4 3 5% 7% 52%	2520
	11th to 20th	Day	12% 7% 2 5% 4 4 4 3 5% 7% 47%	2512
	21st to end	Day	15% 6% 2 4 4 3 4 3 5% 6% 48%	2730
May	1st to 10th	Day	9% 5% 2 5% 3 3 4 4 6% 8% 51%	7655
	11th to 20th	Day	11% 5% 2 4 3 3 3 3 4 7% 55%	7627
	21st to end	Day	15% 6% 2 6% 3 4 4 4 5% 7% 45%	8738
June	1st to 10th	Day	6% 4 1 4 3 3 4 4 6% 9% 57%	2940
	11th to 20th	Day	7% 4 1 4 4 3 4 4 6% 7% 55%	2940
	21st to end	Day	6% 3 2 4 4 3 4 4 5% 8% 58%	2940
July	1st to 10th	Day	6% 3 1 5% 4 4 4 3 5% 8% 57%	8249
	11th to 20th	Day	5% 4 1 3 2 3 3 3 5% 8% 62%	8250
	21st to end	Day	5% 4 2 5% 4 4 5% 4 7% 10% 51%	8812
August	1st to 10th	Day	9% 5% 2 5% 3 3 4 4 6% 8% 50%	5931
	11th to 20th	Day	7% 4 2 5% 3 4 4 4 6% 8% 52%	5868
	21st to end	Day	10% 6% 2 5% 4 4 4 3 5% 7% 50%	6093
September	1st to 10th	Day	8% 4 1 4 3 3 3 3 5% 6% 60%	2377
	11th to 20th	Day	6% 4 1 5% 4 4 4 3 5% 6% 58%	2200
	21st to end	Day	9% 4 1 3 3 3 3 3 3 6% 63%	2200
October	1st to 10th	Day	7% 3 1 2 2 2 2 1 3 4 74%	3590
	11th to 20th	Day	7% 4 1 4 2 3 3 2 4 6% 64%	3235
	21st to end	Day	8% 5% 2 4 3 3 3 3 4 8% 57%	3190
November	1st to 10th	Day	6% 5% 1 4 4 4 3 3 5% 7% 58%	1853
	11th to 20th	Day	5% 6% 2 4 3 3 3 3 4 6% 62%	1890
	21st to end	Day	7% 8% 2 4 3 2 3 3 5% 6% 57%	1890
December	1st to 10th	Day	3 5% 2 5% 3 3 3 3 4 7% 62%	2969
	11th to 20th	Day	4 5% 2 5% 3 4 3 3 4 7% 60%	3106
	21st to end	Day	10% 11% 3 6% 4 4 4 3 5% 6% 44%	4092
January	1st to 10th	Night	6% 10% 4 10% 5% 5% 4 4 4 6% 43%	8201
	11th to 20th	Night	2 6% 3 7% 5% 5% 5% 4 5% 7% 51%	8250
	21st to end	Night	3 8% 3 8% 5% 4 4 4 5% 5% 50%	8878
February	1st to 10th	Night	7% 10% 3 8% 4 4 4 3 6% 6% 44%	2609
	11th to 20th	Night	4 9% 2 8% 6% 4 4 5% 6% 7% 45%	2458
	21st to end	Night	5% 6% 2 7% 4 3 4 3 5% 7% 54%	2076
March	1st to 10th	Night	9% 6% 2 5% 3 3 4 3 4 5% 56%	5494
	11th to 20th	Night	9% 6% 2 4 3 3 3 3 4 6% 57%	5231
	21st to end	Night	9% 8% 3 8% 5% 4 5% 4 6% 8% 39%	5424
April	1st to 10th	Night	12% 7% 2 4 3 3 4 4 6% 8% 47%	2100
	11th to 20th	Night	11% 5% 2 5% 4 5% 4 4 7% 6% 48%	2055
	21st to end	Night	14% 6% 2 5% 4 5% 3 4 5% 7% 44%	1890
May	1st to 10th	Night	14% 6% 2 6% 3 4 4 3 5% 6% 46%	5292
	11th to 20th	Night	8% 5% 2 5% 4 4 4 4 6% 8% 52%	5265
	21st to end	Night	17% 7% 2 6% 4 3 4 3 5% 6% 42%	5465
June	1st to 10th	Night	6% 4 2 4 4 4 4 4 6% 10% 52%	1680
	11th to 20th	Night	9% 4 2 5% 4 4 4 4 5% 10% 50%	1680
	21st to end	Night	7% 4 2 5% 4 4 6% 4 7% 10% 49%	1680
July	1st to 10th	Night	7% 4 2 5% 5% 5% 5% 4 7% 9% 47%	4740
	11th to 20th	Night	5% 4 1 5% 4 3 4 4 6% 7% 57%	4740
	21st to end	Night	6% 5% 2 5% 4 5% 5% 4 8% 9% 46%	5297
August	1st to 10th	Night	7% 6% 3 6% 5% 5% 5% 4 9% 11% 38%	4101
	11th to 20th	Night	8% 4 2 6% 5% 4 5% 4 7% 10% 46%	4197
	21st to end	Night	8% 7% 2 6% 4 4 5% 4 7% 8% 44%	5083
September	1st to 10th	Night	7% 4 1 4 3 3 3 3 6% 7% 59%	2021
	11th to 20th	Night	6% 4 1 4 3 4 4 4 5% 7% 60%	2200
	21st to end	Night	8% 4 1 4 3 3 2 3 4 6% 62%	2200
October	1st to 10th	Night	7% 3 1 2 1 2 2 2 2 4 75%	3590
	11th to 20th	Night	9% 3 1 3 3 3 3 3 3 6% 64%	3871
	21st to end	Night	7% 6% 2 4 3 3 3 3 5% 6% 58%	4610
November	1st to 10th	Night	5% 4 2 5% 3 3 4 3 5% 7% 60%	2665
	11th to 20th	Night	6% 5% 1 5% 4 3 4 4 5% 7% 57%	2730
	21st to end	Night	6% 7% 2 5% 3 3 3 3 5% 7% 55%	2730
December	1st to 10th	Night	4 5% 2 4 3 3 3 3 4 6% 64%	4437
	11th to 20th	Night	4 6% 2 5% 3 3 4 3 6% 7% 58%	5321
	21st to end	Night	12% 11% 3 6% 3 3 3 3 5% 6% 45%	7128

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	38% 3 9% 31% 18% 1	4723
	11th to 20th	Day	34% 6% 10% 27% 20% 4	4740
	21st to end	Day	37% 4 11% 26% 18% 3	5333
February	1st to 10th	Day	40% 5% 15% 21% 15% 4	2027
	11th to 20th	Day	36% 5% 13% 24% 18% 4	2059
	21st to end	Day	28% 4 12% 29% 21% 5%	1730
March	1st to 10th	Day	30% 4 8% 23% 29% 7%	4600
	11th to 20th	Day	27% 4 9% 25% 31% 3	4954
	21st to end	Day	34% 6% 20% 27% 12% 2	5741
April	1st to 10th	Day	31% 5% 16% 28% 17% 3	2520
	11th to 20th	Day	37% 6% 13% 23% 18% 4	2515
	21st to end	Day	36% 5% 12% 28% 17% 2	2730
May	1st to 10th	Day	30% 6% 11% 28% 21% 4	7655
	11th to 20th	Day	30% 5% 10% 27% 23% 5%	7631
	21st to end	Day	38% 7% 13% 26% 14% 3	8739
June	1st to 10th	Day	24% 7% 19% 33% 14% 3	2940
	11th to 20th	Day	26% 7% 14% 27% 20% 7%	2940
	21st to end	Day	23% 7% 12% 29% 24% 6%	2940
July	1st to 10th	Day	25% 5% 11% 29% 26% 4	8181
	11th to 20th	Day	21% 5% 11% 29% 22% 12%	8175
	21st to end	Day	27% 7% 19% 23% 18% 6%	8615
August	1st to 10th	Day	32% 7% 14% 26% 18% 2	4350
	11th to 20th	Day	35% 7% 14% 23% 20% 2	4283
	21st to end	Day	22% 5% 17% 24% 20% 12%	4420
September	1st to 10th	Day	24% 5% 11% 27% 23% 10%	2377
	11th to 20th	Day	25% 6% 12% 26% 26% 5%	2200
	21st to end	Day	25% 4 7% 30% 27% 7%	2200
October	1st to 10th	Day	18% 3 5% 22% 35% 17%	3590
	11th to 20th	Day	23% 3 12% 37% 20% 5%	3235
	21st to end	Day	28% 3 10% 32% 22% 6%	3190
November	1st to 10th	Day	26% 4 13% 29% 21% 6%	1853
	11th to 20th	Day	25% 3 11% 29% 27% 5%	1890
	21st to end	Day	29% 3 13% 28% 22% 4	1890
December	1st to 10th	Day	24% 3 10% 35% 26% 3	2969
	11th to 20th	Day	26% 4 17% 34% 18% 2	3104
	21st to end	Day	40% 5% 9% 31% 13% 2	4092
January	1st to 10th	Night	43% 5% 11% 23% 16% 2	8202
	11th to 20th	Night	31% 5% 15% 27% 20% 2	8250
	21st to end	Night	35% 5% 10% 26% 21% 4	8878
February	1st to 10th	Night	39% 5% 13% 24% 16% 3	2609
	11th to 20th	Night	37% 5% 14% 26% 15% 3	2458
	21st to end	Night	30% 4 11% 26% 23% 6%	2076
March	1st to 10th	Night	30% 4 7% 23% 29% 6%	5494
	11th to 20th	Night	29% 4 8% 23% 27% 10%	5231
	21st to end	Night	41% 8% 17% 21% 11% 1	5424
April	1st to 10th	Night	33% 7% 14% 25% 17% 4	2100
	11th to 20th	Night	35% 6% 13% 24% 18% 4	2055
	21st to end	Night	38% 7% 14% 25% 15% 2	1890
May	1st to 10th	Night	37% 5% 11% 27% 18% 2	5293
	11th to 20th	Night	30% 7% 13% 28% 19% 4	5266
	21st to end	Night	42% 7% 13% 25% 11% 1	5467
June	1st to 10th	Night	28% 8% 23% 27% 13% 2	1680
	11th to 20th	Night	31% 7% 16% 25% 15% 6%	1680
	21st to end	Night	28% 8% 16% 24% 20% 3	1680
July	1st to 10th	Night	32% 5% 16% 29% 16% 1	4700
	11th to 20th	Night	26% 5% 14% 24% 21% 10%	4692
	21st to end	Night	32% 6% 17% 23% 16% 5%	5181
August	1st to 10th	Night	33% 8% 17% 27% 13% 2	3006
	11th to 20th	Night	37% 7% 15% 23% 16% 2	3058
	21st to end	Night	26% 6% 15% 25% 18% 9%	3687
September	1st to 10th	Night	24% 5% 11% 26% 25% 9%	2021
	11th to 20th	Night	24% 6% 13% 27% 23% 7%	2200
	21st to end	Night	24% 5% 8% 26% 29% 7%	2200
October	1st to 10th	Night	17% 3 6% 18% 45% 10%	3590
	11th to 20th	Night	23% 3 9% 30% 26% 8%	3871
	21st to end	Night	28% 4 11% 27% 25% 6%	4610
November	1st to 10th	Night	24% 4 12% 30% 23% 7%	2665
	11th to 20th	Night	26% 5% 12% 28% 24% 7%	2730
	21st to end	Night	29% 4 11% 29% 22% 5%	2730
December	1st to 10th	Night	22% 3 15% 37% 20% 3	4437
	11th to 20th	Night	26% 3 14% 37% 17% 3	5322
	21st to end	Night	40% 4 10% 31% 14% 1	7128

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	13% 5% 40% 30% 12% 1	330
	11th to 20th	Day	11% 15% 34% 35% 5% 1	330
	21st to end	Day	8% 9% 47% 24% 9% 2	363
February	1st to 10th	Day	7% 15% 48% 27% 4	330
	11th to 20th	Day	11% 8% 44% 28% 7% 2	330
	21st to end	Day	10% 11% 51% 22% 6%	273
March	1st to 10th	Day	12% 12% 38% 26% 10% 2	330
	11th to 20th	Day	13% 9% 35% 32% 9% 2	330
	21st to end	Day	17% 14% 41% 18% 8% 1	429
April	1st to 10th	Day	12% 19% 39% 24% 7% 1	540
	11th to 20th	Day	15% 21% 32% 25% 7% 1	553
	21st to end	Day	19% 14% 32% 25% 9% 1	750
May	1st to 10th	Day	13% 11% 33% 29% 11% 3	753
	11th to 20th	Day	17% 9% 33% 28% 11% 3	775
	21st to end	Day	16% 9% 30% 28% 15% 2	844
June	1st to 10th	Day	7% 6% 27% 31% 21% 8%	780
	11th to 20th	Day	7% 9% 33% 37% 12% 2	780
	21st to end	Day	8% 6% 29% 38% 18% 2	780
July	1st to 10th	Day	6% 3 25% 40% 23% 4	771
	11th to 20th	Day	4 3 21% 43% 24% 5%	768
	21st to end	Day	6% 3 18% 43% 26% 5%	849
August	1st to 10th	Day	9% 4 19% 41% 24% 3	776
	11th to 20th	Day	8% 3 22% 42% 22% 3	734
	21st to end	Day	7% 3 25% 40% 21% 5%	620
September	1st to 10th	Day	8% 4 22% 40% 20% 5%	507
	11th to 20th	Day	4 5% 21% 39% 25% 6%	330
	21st to end	Day	14% 7% 26% 29% 20% 3	330
October	1st to 10th	Day	14% 6% 22% 32% 21% 6%	330
	11th to 20th	Day	9% 12% 37% 31% 8% 3	330
	21st to end	Day	14% 13% 29% 28% 12% 3	363
November	1st to 10th	Day	11% 7% 41% 24% 15% 3	330
	11th to 20th	Day	9% 9% 40% 29% 10% 2	330
	21st to end	Day	14% 9% 35% 28% 11% 3	330
December	1st to 10th	Day	5% 11% 46% 29% 8% 1	330
	11th to 20th	Day	11% 14% 36% 31% 8%	330
	21st to end	Day	12% 13% 41% 27% 6% 1	363
January	1st to 10th	Night	8% 9% 39% 35% 8%	1050
	11th to 20th	Night	7% 12% 43% 31% 6% 1	1050
	21st to end	Night	7% 8% 46% 33% 6%	1155
February	1st to 10th	Night	11% 11% 46% 28% 5%	929
	11th to 20th	Night	8% 10% 46% 33% 4	824
	21st to end	Night	8% 10% 48% 30% 5%	692
March	1st to 10th	Night	11% 10% 41% 34% 4	840
	11th to 20th	Night	11% 10% 43% 31% 5%	693
	21st to end	Night	13% 10% 43% 29% 5%	693
April	1st to 10th	Night	16% 13% 43% 27% 1	630
	11th to 20th	Night	13% 15% 45% 26% 2	623
	21st to end	Night	17% 12% 33% 31% 7%	630
May	1st to 10th	Night	13% 8% 37% 33% 8%	630
	11th to 20th	Night	16% 8% 35% 33% 7% 1	621
	21st to end	Night	17% 8% 35% 31% 9%	683
June	1st to 10th	Night	6% 7% 33% 41% 12% 1	630
	11th to 20th	Night	11% 7% 40% 33% 9%	630
	21st to end	Night	7% 5% 33% 46% 8%	630
July	1st to 10th	Night	6% 4 32% 43% 15%	615
	11th to 20th	Night	3 3 28% 52% 14% 1	612
	21st to end	Night	4 2 23% 54% 16%	690
August	1st to 10th	Night	5% 3 22% 54% 15%	627
	11th to 20th	Night	7% 3 26% 51% 13%	624
	21st to end	Night	5% 1 29% 49% 15% 1	687
September	1st to 10th	Night	8% 3 29% 47% 13% 1	600
	11th to 20th	Night	8% 4 31% 43% 13% 1	600
	21st to end	Night	10% 6% 32% 38% 13% 1	600
October	1st to 10th	Night	14% 6% 31% 37% 11%	600
	11th to 20th	Night	10% 9% 34% 36% 10% 1	774
	21st to end	Night	12% 10% 35% 32% 10% 1	1100
November	1st to 10th	Night	6% 7% 41% 38% 7% 1	1025
	11th to 20th	Night	8% 8% 41% 36% 7%	1050
	21st to end	Night	9% 7% 37% 36% 11%	1050
December	1st to 10th	Night	9% 10% 41% 35% 5%	1050
	11th to 20th	Night	10% 10% 39% 34% 7%	1050
	21st to end	Night	13% 10% 36% 35% 5%	1155

Page generated at 2026-08-27 03:07:11. Version ac07

Copyright © 2026 Attilla Danko.