Estes park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Estes park clear sky chart from 2005-11-06 to 2026-03-03.

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	3 5% 2 6% 4 4 5% 4 7% 8% 50%	139955
	Night	2 5% 2 5% 3 3 4 3 5% 8% 60%	138729
Transparency	Day	27% 8% 11% 24% 22% 8%	134883
	Night	21% 6% 13% 27% 24% 9%	134808
Seeing	Day	12% 26% 31% 20% 8% 2	17355
	Night	8% 29% 29% 22% 10% 2	27531

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	1 4 3 10% 4 3 2 2 4 6% 61%	4720
	11th to 20th	Day	2 1 6% 5% 3 3 3 5% 8% 62%	4897
	21st to end	Day	3 2 7% 4 3 4 3 5% 7% 61%	5844
February	1st to 10th	Day	1 5% 2 8% 4 3 4 4 6% 8% 56%	1890
	11th to 20th	Day	4 2 6% 4 2 4 4 7% 8% 59%	1978
	21st to end	Day	1 5% 3 7% 3 3 4 3 6% 9% 58%	1730
March	1st to 10th	Day	1 6% 4 8% 4 4 4 4 5% 6% 53%	4520
	11th to 20th	Day	1 9% 5% 9% 4 5% 4 4 6% 9% 44%	5000
	21st to end	Day	1 6% 3 6% 3 4 4 4 6% 11% 50%	5783
April	1st to 10th	Day	3 6% 3 5% 4 4 4 4 7% 8% 52%	2400
	11th to 20th	Day	6% 10% 4 9% 5% 4 4 3 6% 8% 41%	2371
	21st to end	Day	5% 11% 3 7% 5% 4 5% 5% 7% 9% 39%	2400
May	1st to 10th	Day	8% 12% 3 6% 5% 5% 5% 4 6% 8% 37%	5839
	11th to 20th	Day	6% 7% 2 6% 4 6% 6% 5% 7% 9% 42%	6298
	21st to end	Day	5% 5% 2 6% 4 5% 6% 6% 7% 9% 44%	6925
June	1st to 10th	Day	4 5% 2 4 5% 5% 6% 6% 9% 9% 44%	2800
	11th to 20th	Day	5% 4 1 5% 4 5% 5% 4 7% 8% 51%	2800
	21st to end	Day	3 4 2 6% 5% 5% 6% 6% 7% 9% 47%	2800
July	1st to 10th	Day	4 3 2 5% 4 5% 6% 6% 8% 10% 48%	6339
	11th to 20th	Day	2 3 2 7% 6% 6% 8% 7% 10% 10% 39%	6340
	21st to end	Day	4 4 2 7% 6% 6% 7% 6% 8% 9% 41%	6771
August	1st to 10th	Day	5% 4 2 6% 5% 6% 7% 6% 9% 11% 38%	5779
	11th to 20th	Day	3 3 1 5% 4 6% 7% 5% 8% 10% 48%	5458
	21st to end	Day	6% 6% 3 8% 5% 5% 6% 5% 7% 8% 42%	5984
September	1st to 10th	Day	5% 4 1 6% 4 4 4 5% 6% 7% 52%	2400
	11th to 20th	Day	6% 4 1 5% 4 4 5% 4 6% 7% 55%	2400
	21st to end	Day	6% 6% 1 5% 2 4 3 3 5% 6% 60%	2175
October	1st to 10th	Day	3 4 2 4 3 3 3 3 3 4 67%	3270
	11th to 20th	Day	4 4 1 5% 3 4 4 3 6% 9% 56%	3250
	21st to end	Day	2 6% 2 4 3 3 3 3 4 7% 63%	3436
November	1st to 10th	Day	2 4 1 4 3 3 3 3 5% 9% 63%	1853
	11th to 20th	Day	1 5% 2 3 2 2 4 4 5% 11% 62%	1890
	21st to end	Day	1 4 2 5% 4 3 4 3 7% 7% 59%	1717
December	1st to 10th	Day	2 1 5% 2 2 2 2 4 7% 71%	2700
	11th to 20th	Day	1 3 2 4 3 3 3 3 6% 8% 65%	3106
	21st to end	Day	1 6% 3 7% 4 4 3 3 6% 8% 54%	4092
January	1st to 10th	Night	3 2 8% 4 3 4 3 5% 8% 60%	8201
	11th to 20th	Night	2 1 4 4 3 4 3 5% 7% 68%	8148
	21st to end	Night	4 2 4 3 4 4 3 5% 6% 64%	8370
February	1st to 10th	Night	5% 3 5% 3 4 3 3 5% 9% 61%	2730
	11th to 20th	Night	4 3 5% 3 3 4 4 4 8% 62%	2528
	21st to end	Night	5% 3 6% 3 3 3 2 5% 7% 62%	2076
March	1st to 10th	Night	6% 4 8% 4 3 4 3 4 7% 57%	5382
	11th to 20th	Night	1 9% 4 5% 3 3 3 3 5% 9% 54%	5000
	21st to end	Night	2 6% 2 6% 4 4 4 3 5% 8% 56%	5178
April	1st to 10th	Night	1 6% 2 5% 3 4 4 4 6% 7% 57%	2000
	11th to 20th	Night	4 8% 2 7% 3 2 4 3 5% 7% 54%	1977
	21st to end	Night	7% 9% 3 5% 3 2 4 4 5% 9% 49%	2000
May	1st to 10th	Night	9% 10% 2 6% 4 4 4 4 4 7% 47%	4134
	11th to 20th	Night	6% 8% 2 6% 5% 4 4 3 5% 7% 50%	3617
	21st to end	Night	5% 6% 2 4 3 3 3 3 5% 6% 59%	3972
June	1st to 10th	Night	5% 4 1 3 3 3 3 4 6% 10% 58%	1600
	11th to 20th	Night	4 3 1 3 3 3 4 3 5% 9% 62%	1600
	21st to end	Night	4 3 1 3 3 3 4 4 7% 9% 60%	1600
July	1st to 10th	Night	3 4 2 4 3 3 4 4 7% 8% 59%	3640
	11th to 20th	Night	3 3 1 3 2 3 5% 5% 8% 11% 55%	3640
	21st to end	Night	3 3 1 4 4 4 5% 4 7% 8% 57%	4098
August	1st to 10th	Night	5% 3 1 4 3 4 5% 5% 10% 12% 47%	4033
	11th to 20th	Night	2 3 1 4 3 4 4 4 6% 9% 61%	4390
	21st to end	Night	5% 5% 2 5% 3 5% 4 4 6% 9% 52%	4993
September	1st to 10th	Night	5% 4 2 5% 3 4 3 3 5% 6% 61%	2000
	11th to 20th	Night	5% 4 1 3 3 3 3 3 5% 6% 65%	2000
	21st to end	Night	6% 4 1 3 3 3 3 3 4 6% 64%	2220
October	1st to 10th	Night	3 3 1 3 2 2 2 2 4 4 75%	3920
	11th to 20th	Night	3 5% 1 4 3 3 3 3 5% 7% 63%	3898
	21st to end	Night	2 5% 2 4 3 4 3 2 4 7% 65%	4329
November	1st to 10th	Night	2 3 2 4 2 3 3 3 4 8% 67%	2665
	11th to 20th	Night	1 4 2 4 3 3 3 3 6% 8% 65%	2730
	21st to end	Night	1 4 3 5% 3 3 3 4 6% 7% 61%	2901
December	1st to 10th	Night	2 1 3 2 2 2 2 4 6% 76%	4710
	11th to 20th	Night	1 4 2 5% 2 2 3 3 4 8% 67%	5321
	21st to end	Night	1 6% 3 7% 4 4 4 3 6% 8% 55%	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	24% 5% 11% 26% 28% 6%	4723
	11th to 20th	Day	19% 6% 15% 26% 20% 14%	4897
	21st to end	Day	20% 6% 10% 26% 25% 13%	5844
February	1st to 10th	Day	26% 7% 16% 26% 19% 6%	1890
	11th to 20th	Day	22% 7% 12% 32% 22% 6%	1987
	21st to end	Day	24% 7% 12% 23% 27% 7%	1730
March	1st to 10th	Day	26% 9% 8% 23% 27% 7%	4520
	11th to 20th	Day	31% 8% 12% 24% 21% 3	5000
	21st to end	Day	25% 9% 14% 37% 14% 1	5783
April	1st to 10th	Day	28% 7% 12% 26% 20% 6%	2400
	11th to 20th	Day	39% 6% 12% 20% 20% 3	2374
	21st to end	Day	39% 8% 11% 27% 14% 1	2400
May	1st to 10th	Day	41% 9% 9% 23% 17% 1	5839
	11th to 20th	Day	32% 9% 11% 21% 20% 6%	6302
	21st to end	Day	29% 11% 10% 22% 24% 3	6926
June	1st to 10th	Day	30% 10% 17% 22% 16% 5%	2800
	11th to 20th	Day	27% 7% 11% 19% 24% 12%	2800
	21st to end	Day	29% 9% 10% 20% 22% 11%	2800
July	1st to 10th	Day	26% 7% 9% 16% 23% 20%	6271
	11th to 20th	Day	30% 12% 12% 21% 15% 10%	6265
	21st to end	Day	33% 10% 11% 16% 15% 15%	6575
August	1st to 10th	Day	38% 12% 13% 17% 14% 7%	4208
	11th to 20th	Day	30% 11% 11% 16% 19% 13%	3951
	21st to end	Day	28% 9% 10% 17% 25% 11%	4311
September	1st to 10th	Day	26% 9% 7% 20% 25% 12%	2400
	11th to 20th	Day	26% 9% 9% 20% 25% 11%	2400
	21st to end	Day	25% 5% 7% 23% 33% 8%	2175
October	1st to 10th	Day	19% 5% 6% 17% 32% 20%	3270
	11th to 20th	Day	24% 7% 9% 31% 23% 6%	3250
	21st to end	Day	21% 5% 8% 27% 33% 6%	3436
November	1st to 10th	Day	19% 5% 13% 27% 31% 5%	1853
	11th to 20th	Day	17% 5% 15% 30% 25% 8%	1890
	21st to end	Day	22% 6% 12% 31% 20% 9%	1717
December	1st to 10th	Day	14% 5% 11% 34% 28% 7%	2700
	11th to 20th	Day	15% 7% 12% 37% 26% 4	3104
	21st to end	Day	25% 7% 10% 27% 22% 9%	4092
January	1st to 10th	Night	22% 5% 9% 33% 23% 8%	8202
	11th to 20th	Night	17% 6% 16% 24% 24% 14%	8148
	21st to end	Night	20% 5% 11% 23% 26% 15%	8370
February	1st to 10th	Night	21% 5% 18% 30% 21% 6%	2730
	11th to 20th	Night	21% 4 14% 34% 22% 4	2529
	21st to end	Night	22% 5% 12% 25% 26% 10%	2076
March	1st to 10th	Night	25% 6% 8% 22% 28% 11%	5382
	11th to 20th	Night	26% 5% 11% 22% 27% 10%	5000
	21st to end	Night	24% 6% 18% 33% 17% 2	5178
April	1st to 10th	Night	25% 6% 14% 30% 21% 6%	2000
	11th to 20th	Night	30% 5% 14% 29% 20% 4	1977
	21st to end	Night	31% 6% 12% 31% 19% 1	2000
May	1st to 10th	Night	33% 7% 13% 28% 16% 2	4131
	11th to 20th	Night	32% 6% 14% 27% 17% 3	3618
	21st to end	Night	24% 6% 13% 28% 25% 3	3972
June	1st to 10th	Night	22% 7% 20% 30% 16% 5%	1600
	11th to 20th	Night	19% 6% 12% 22% 25% 15%	1600
	21st to end	Night	19% 7% 10% 25% 27% 13%	1600
July	1st to 10th	Night	21% 6% 8% 18% 28% 19%	3600
	11th to 20th	Night	18% 7% 19% 29% 18% 9%	3592
	21st to end	Night	23% 7% 16% 24% 16% 15%	3982
August	1st to 10th	Night	27% 9% 18% 22% 20% 4	2928
	11th to 20th	Night	22% 8% 20% 21% 20% 9%	3173
	21st to end	Night	21% 7% 14% 23% 27% 7%	3597
September	1st to 10th	Night	24% 5% 9% 22% 28% 13%	2000
	11th to 20th	Night	19% 6% 10% 27% 25% 12%	2000
	21st to end	Night	22% 4 8% 29% 28% 9%	2220
October	1st to 10th	Night	14% 3 6% 24% 33% 19%	3920
	11th to 20th	Night	20% 5% 11% 32% 26% 7%	3898
	21st to end	Night	18% 4 10% 30% 31% 8%	4329
November	1st to 10th	Night	16% 6% 13% 27% 28% 9%	2665
	11th to 20th	Night	16% 5% 13% 33% 26% 7%	2730
	21st to end	Night	20% 5% 12% 31% 24% 8%	2901
December	1st to 10th	Night	11% 3 13% 36% 31% 7%	4710
	11th to 20th	Night	15% 6% 11% 33% 31% 5%	5322
	21st to end	Night	25% 7% 11% 23% 26% 8%	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	15% 41% 25% 11% 7% 1	330
	11th to 20th	Day	15% 45% 25% 12% 3	330
	21st to end	Day	9% 47% 28% 13% 3 1	363
February	1st to 10th	Day	14% 54% 25% 5% 1 1	330
	11th to 20th	Day	18% 48% 24% 9% 1	330
	21st to end	Day	26% 43% 20% 10% 1	273
March	1st to 10th	Day	17% 41% 30% 10% 2	306
	11th to 20th	Day	14% 34% 34% 14% 3	500
	21st to end	Day	16% 38% 33% 10% 2	550
April	1st to 10th	Day	16% 38% 33% 10% 3	500
	11th to 20th	Day	21% 37% 30% 9% 2 1	492
	21st to end	Day	18% 28% 35% 14% 4 1	500
May	1st to 10th	Day	19% 27% 33% 15% 4 1	618
	11th to 20th	Day	19% 18% 35% 19% 8% 1	725
	21st to end	Day	13% 18% 31% 25% 10% 2	789
June	1st to 10th	Day	7% 17% 32% 25% 15% 4	730
	11th to 20th	Day	10% 19% 36% 23% 9% 2	730
	21st to end	Day	7% 15% 35% 26% 14% 4	730
July	1st to 10th	Day	7% 7% 32% 32% 17% 5%	721
	11th to 20th	Day	6% 8% 34% 31% 16% 6%	718
	21st to end	Day	6% 7% 28% 35% 18% 5%	737
August	1st to 10th	Day	9% 15% 32% 30% 11% 2	527
	11th to 20th	Day	8% 12% 33% 31% 12% 4	517
	21st to end	Day	10% 15% 31% 29% 12% 3	583
September	1st to 10th	Day	8% 13% 33% 30% 14% 2	530
	11th to 20th	Day	7% 20% 37% 22% 12% 2	530
	21st to end	Day	10% 18% 32% 25% 12% 3	330
October	1st to 10th	Day	8% 22% 33% 25% 8% 4	330
	11th to 20th	Day	12% 38% 28% 15% 6% 2	330
	21st to end	Day	10% 40% 31% 15% 2 1	363
November	1st to 10th	Day	15% 41% 24% 12% 6% 1	330
	11th to 20th	Day	14% 41% 30% 10% 4 1	330
	21st to end	Day	11% 37% 37% 12% 2 1	330
December	1st to 10th	Day	17% 41% 26% 13% 3 1	330
	11th to 20th	Day	16% 52% 22% 8% 2	330
	21st to end	Day	18% 46% 23% 11% 2 1	363
January	1st to 10th	Night	8% 44% 27% 14% 6% 1	1050
	11th to 20th	Night	10% 48% 25% 11% 5% 1	1013
	21st to end	Night	7% 45% 33% 11% 3	924
February	1st to 10th	Night	6% 52% 28% 10% 3	840
	11th to 20th	Night	8% 43% 33% 13% 2	824
	21st to end	Night	12% 46% 25% 14% 2	692
March	1st to 10th	Night	5% 43% 32% 14% 5%	808
	11th to 20th	Night	8% 34% 31% 21% 7%	800
	21st to end	Night	11% 34% 32% 19% 3 1	750
April	1st to 10th	Night	12% 28% 40% 17% 3	600
	11th to 20th	Night	11% 30% 32% 22% 5% 1	593
	21st to end	Night	14% 24% 32% 21% 8% 1	600
May	1st to 10th	Night	14% 17% 34% 26% 9% 2	600
	11th to 20th	Night	18% 9% 29% 30% 13% 2	591
	21st to end	Night	8% 14% 30% 31% 17% 1	650
June	1st to 10th	Night	7% 8% 29% 34% 20% 3	600
	11th to 20th	Night	6% 12% 34% 36% 11% 1	600
	21st to end	Night	6% 7% 26% 37% 21% 3	600
July	1st to 10th	Night	6% 5% 17% 40% 29% 3	585
	11th to 20th	Night	3 3 23% 40% 26% 5%	582
	21st to end	Night	6% 2 16% 40% 32% 4	657
August	1st to 10th	Night	6% 5% 20% 41% 25% 4	597
	11th to 20th	Night	6% 4 21% 44% 22% 4	594
	21st to end	Night	5% 6% 19% 38% 26% 6%	660
September	1st to 10th	Night	7% 4 27% 38% 20% 5%	600
	11th to 20th	Night	7% 12% 28% 34% 16% 4	600
	21st to end	Night	9% 10% 30% 32% 15% 4	620
October	1st to 10th	Night	9% 21% 31% 27% 10% 2	800
	11th to 20th	Night	7% 29% 35% 20% 6% 2	800
	21st to end	Night	8% 32% 38% 15% 6% 2	921
November	1st to 10th	Night	7% 38% 33% 16% 6% 1	1025
	11th to 20th	Night	9% 46% 31% 10% 3 1	1050
	21st to end	Night	6% 38% 35% 17% 3	1050
December	1st to 10th	Night	10% 44% 30% 14% 2	1050
	11th to 20th	Night	11% 46% 28% 11% 3	1050
	21st to end	Night	10% 47% 25% 12% 4 1	1155

Page generated at 2026-02-27 23:40:22. Version ac07

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