Scofield State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Scofield State Park clear sky chart from 2005-11-06 to 2026-09-14.

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 6% 3 7% 5% 5% 5% 4 6% 7% 50%	157296
	Night	2 5% 2 7% 5% 4 4 4 6% 7% 55%	151420
Transparency	Day	31% 3 9% 22% 23% 13%	152068
	Night	26% 3 10% 26% 23% 12%	147655
Seeing	Day	13% 20% 32% 22% 10% 3	17432
	Night	8% 15% 25% 31% 18% 3	27823

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 6% 5% 12% 6% 6% 5% 5% 7% 9% 40%	5318
	11th to 20th	Day	4 2 9% 7% 5% 4 4 5% 5% 54%	5340
	21st to end	Day	1 6% 4 8% 3 3 4 3 5% 7% 55%	5844
February	1st to 10th	Day	1 8% 4 10% 6% 5% 4 4 6% 7% 45%	1890
	11th to 20th	Day	3 10% 5% 10% 5% 3 5% 5% 7% 8% 39%	1892
	21st to end	Day	2 9% 4 10% 6% 5% 5% 4 5% 7% 44%	1730
March	1st to 10th	Day	1 9% 6% 11% 5% 4 4 3 6% 7% 43%	5036
	11th to 20th	Day	2 12% 4 13% 5% 4 5% 4 5% 6% 40%	5110
	21st to end	Day	2 14% 5% 12% 6% 6% 7% 4 5% 5% 32%	5607
April	1st to 10th	Day	3 9% 3 8% 5% 5% 6% 4 6% 7% 44%	2357
	11th to 20th	Day	4 9% 2 9% 6% 6% 5% 4 6% 6% 43%	2575
	21st to end	Day	5% 10% 3 7% 5% 5% 4 3 6% 7% 45%	2730
May	1st to 10th	Day	5% 8% 3 7% 4 4 5% 4 6% 6% 48%	7626
	11th to 20th	Day	4 8% 3 6% 5% 5% 6% 5% 7% 7% 45%	7596
	21st to end	Day	3 6% 2 6% 5% 5% 6% 5% 6% 8% 50%	8370
June	1st to 10th	Day	4 5% 1 5% 3 4 4 4 6% 8% 56%	2803
	11th to 20th	Day	4 4 1 5% 3 3 3 3 4 6% 63%	2936
	21st to end	Day	3 4 1 4 3 4 4 3 5% 6% 63%	2730
July	1st to 10th	Day	3 3 1 4 3 4 5% 3 5% 5% 64%	7649
	11th to 20th	Day	2 3 2 6% 6% 6% 6% 5% 8% 8% 48%	7650
	21st to end	Day	3 4 2 6% 5% 5% 6% 5% 7% 9% 48%	8304
August	1st to 10th	Day	2 3 1 4 3 4 5% 4 6% 7% 61%	7549
	11th to 20th	Day	2 2 1 5% 5% 5% 6% 5% 7% 8% 53%	7565
	21st to end	Day	4 3 2 7% 6% 6% 7% 6% 8% 8% 43%	8169
September	1st to 10th	Day	4 4 2 5% 4 4 4 3 5% 6% 59%	2416
	11th to 20th	Day	5% 4 1 5% 4 4 3 3 5% 6% 60%	2234
	21st to end	Day	5% 4 2 4 3 3 3 2 5% 5% 64%	2200
October	1st to 10th	Day	5% 5% 1 4 3 3 2 3 4 4 67%	3383
	11th to 20th	Day	7% 6% 2 5% 3 4 3 3 4 8% 55%	3250
	21st to end	Day	3 5% 2 5% 2 3 4 3 4 5% 63%	3548
November	1st to 10th	Day	3 7% 2 6% 3 3 3 4 6% 8% 56%	1924
	11th to 20th	Day	2 6% 3 5% 3 3 5% 4 6% 7% 56%	1890
	21st to end	Day	2 6% 3 7% 5% 3 4 4 6% 8% 53%	1725
December	1st to 10th	Day	1 4 2 6% 4 4 3 3 5% 8% 61%	2700
	11th to 20th	Day	1 5% 2 7% 4 4 5% 5% 8% 12% 47%	3106
	21st to end	Day	1 6% 4 11% 6% 6% 6% 5% 8% 8% 39%	4544
January	1st to 10th	Night	1 5% 3 16% 10% 6% 5% 4 6% 7% 38%	7605
	11th to 20th	Night	2 2 10% 7% 6% 4 3 5% 7% 54%	7650
	21st to end	Night	1 6% 3 9% 4 3 3 3 5% 7% 55%	8370
February	1st to 10th	Night	1 6% 3 6% 5% 6% 4 5% 6% 9% 49%	2730
	11th to 20th	Night	1 6% 3 8% 5% 5% 5% 5% 7% 9% 45%	2611
	21st to end	Night	2 5% 3 6% 5% 4 5% 5% 7% 7% 51%	2076
March	1st to 10th	Night	1 7% 5% 9% 5% 4 5% 4 6% 7% 49%	5078
	11th to 20th	Night	1 8% 3 12% 6% 5% 5% 4 6% 8% 41%	5110
	21st to end	Night	1 7% 3 10% 5% 4 4 4 6% 8% 48%	5610
April	1st to 10th	Night	2 6% 2 6% 5% 4 4 4 6% 7% 53%	2263
	11th to 20th	Night	3 6% 3 6% 4 4 4 4 6% 8% 51%	1990
	21st to end	Night	3 6% 2 5% 4 4 4 4 7% 9% 52%	1890
May	1st to 10th	Night	4 7% 2 7% 5% 4 4 4 6% 7% 50%	5321
	11th to 20th	Night	3 5% 2 5% 5% 4 4 4 5% 6% 58%	5296
	21st to end	Night	3 4 1 4 3 3 4 3 6% 8% 60%	5837
June	1st to 10th	Night	3 4 1 3 3 4 3 5% 7% 9% 58%	1805
	11th to 20th	Night	3 2 1 4 2 3 4 3 4 5% 68%	1680
	21st to end	Night	2 1 1 3 3 4 5% 3 5% 6% 67%	1879
July	1st to 10th	Night	2 2 1 4 3 3 4 3 4 5% 68%	5340
	11th to 20th	Night	3 4 1 5% 4 5% 5% 5% 8% 9% 51%	5340
	21st to end	Night	3 3 1 5% 4 4 5% 5% 7% 8% 54%	5805
August	1st to 10th	Night	2 2 1 4 3 4 4 4 5% 7% 63%	5273
	11th to 20th	Night	3 3 2 5% 4 4 5% 4 6% 8% 56%	5291
	21st to end	Night	2 3 2 5% 5% 6% 5% 5% 7% 9% 52%	6047
September	1st to 10th	Night	3 3 1 4 2 2 3 3 5% 7% 66%	2200
	11th to 20th	Night	3 2 1 3 3 4 3 3 4 7% 67%	2233
	21st to end	Night	4 3 1 4 2 3 2 2 3 5% 69%	2200
October	1st to 10th	Night	3 3 1 3 2 2 2 2 4 6% 72%	3809
	11th to 20th	Night	4 4 2 5% 3 3 4 4 6% 7% 60%	3898
	21st to end	Night	3 5% 2 4 3 2 3 2 5% 7% 63%	4252
November	1st to 10th	Night	2 5% 2 5% 4 3 4 4 5% 7% 60%	2595
	11th to 20th	Night	1 4 2 5% 4 4 4 4 7% 8% 58%	2730
	21st to end	Night	2 6% 2 7% 4 4 4 4 6% 8% 54%	2870
December	1st to 10th	Night	1 4 2 6% 4 3 3 3 5% 7% 62%	4710
	11th to 20th	Night	1 5% 2 5% 5% 5% 4 5% 7% 9% 52%	5321
	21st to end	Night	2 8% 3 9% 7% 5% 5% 5% 7% 9% 42%	6705

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	37% 4 16% 29% 12% 2	5321
	11th to 20th	Day	26% 3 13% 26% 25% 8%	5340
	21st to end	Day	27% 2 13% 24% 28% 7%	5844
February	1st to 10th	Day	35% 6% 18% 22% 15% 5%	1890
	11th to 20th	Day	37% 4 15% 25% 16% 2	1901
	21st to end	Day	37% 3 11% 29% 16% 4	1730
March	1st to 10th	Day	39% 2 7% 26% 19% 7%	5036
	11th to 20th	Day	44% 2 10% 26% 15% 2	5110
	21st to end	Day	49% 3 13% 24% 10% 1	5607
April	1st to 10th	Day	36% 4 10% 26% 20% 4	2357
	11th to 20th	Day	38% 3 9% 26% 21% 3	2578
	21st to end	Day	36% 3 7% 31% 21% 2	2730
May	1st to 10th	Day	33% 2 6% 25% 29% 6%	7626
	11th to 20th	Day	36% 3 3 22% 32% 4	7599
	21st to end	Day	31% 3 4 24% 34% 4	8371
June	1st to 10th	Day	26% 3 6% 21% 34% 10%	2803
	11th to 20th	Day	23% 3 4 15% 31% 24%	2936
	21st to end	Day	22% 4 2 13% 28% 32%	2730
July	1st to 10th	Day	21% 5% 1 6% 15% 52%	7586
	11th to 20th	Day	30% 4 8% 14% 19% 26%	7581
	21st to end	Day	29% 5% 7% 17% 19% 23%	8120
August	1st to 10th	Day	26% 4 7% 18% 16% 29%	5978
	11th to 20th	Day	29% 5% 10% 22% 21% 13%	5964
	21st to end	Day	30% 4 11% 22% 16% 17%	6412
September	1st to 10th	Day	26% 4 6% 15% 26% 24%	2416
	11th to 20th	Day	27% 3 6% 18% 27% 19%	2234
	21st to end	Day	23% 3 4 20% 36% 14%	2200
October	1st to 10th	Day	22% 2 4 16% 39% 17%	3383
	11th to 20th	Day	29% 2 4 29% 30% 5%	3250
	21st to end	Day	22% 2 8% 35% 29% 5%	3548
November	1st to 10th	Day	26% 4 12% 28% 24% 6%	1924
	11th to 20th	Day	24% 4 17% 30% 22% 2	1890
	21st to end	Day	27% 2 13% 31% 21% 5%	1725
December	1st to 10th	Day	20% 4 13% 35% 24% 4	2700
	11th to 20th	Day	26% 3 20% 31% 18% 2	3104
	21st to end	Day	38% 4 14% 19% 18% 7%	4544
January	1st to 10th	Night	39% 2 14% 25% 16% 3	7605
	11th to 20th	Night	23% 3 13% 29% 23% 9%	7650
	21st to end	Night	26% 2 13% 23% 28% 8%	8370
February	1st to 10th	Night	27% 5% 19% 29% 16% 4	2730
	11th to 20th	Night	30% 5% 12% 28% 22% 3	2612
	21st to end	Night	25% 3 13% 32% 20% 6%	2076
March	1st to 10th	Night	32% 2 9% 31% 20% 7%	5078
	11th to 20th	Night	41% 2 8% 30% 15% 3	5110
	21st to end	Night	30% 2 17% 31% 18% 2	5610
April	1st to 10th	Night	26% 5% 13% 27% 23% 6%	2263
	11th to 20th	Night	28% 4 9% 31% 24% 4	1990
	21st to end	Night	25% 2 11% 36% 23% 2	1890
May	1st to 10th	Night	30% 2 5% 28% 29% 5%	5319
	11th to 20th	Night	27% 3 4 27% 33% 6%	5297
	21st to end	Night	23% 2 6% 29% 37% 3	5838
June	1st to 10th	Night	22% 3 7% 26% 32% 10%	1805
	11th to 20th	Night	18% 3 5% 16% 32% 26%	1680
	21st to end	Night	17% 3 3 12% 30% 36%	1879
July	1st to 10th	Night	18% 3 2 7% 17% 53%	5295
	11th to 20th	Night	27% 2 9% 13% 19% 29%	5286
	21st to end	Night	25% 5% 9% 17% 19% 25%	5677
August	1st to 10th	Night	24% 2 7% 17% 17% 33%	4168
	11th to 20th	Night	29% 4 13% 23% 16% 15%	4168
	21st to end	Night	23% 4 10% 24% 21% 18%	4735
September	1st to 10th	Night	18% 3 7% 18% 28% 26%	2200
	11th to 20th	Night	19% 2 8% 23% 27% 22%	2233
	21st to end	Night	20% 2 4 19% 37% 19%	2200
October	1st to 10th	Night	15% 2 4 18% 36% 25%	3809
	11th to 20th	Night	22% 2 5% 33% 30% 7%	3898
	21st to end	Night	20% 2 7% 35% 32% 4	4252
November	1st to 10th	Night	22% 3 11% 32% 25% 8%	2595
	11th to 20th	Night	20% 3 15% 35% 23% 3	2730
	21st to end	Night	26% 3 12% 28% 24% 7%	2870
December	1st to 10th	Night	20% 3 12% 35% 25% 5%	4710
	11th to 20th	Night	25% 3 17% 37% 16% 2	5322
	21st to end	Night	34% 4 15% 25% 15% 6%	6705

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	19% 22% 30% 21% 6% 2	330
	11th to 20th	Day	20% 23% 25% 23% 6% 2	330
	21st to end	Day	12% 29% 31% 19% 8% 1	363
February	1st to 10th	Day	18% 33% 30% 12% 6% 1	330
	11th to 20th	Day	18% 32% 30% 14% 5% 1	377
	21st to end	Day	16% 32% 35% 13% 3	446
March	1st to 10th	Day	16% 28% 34% 17% 5%	540
	11th to 20th	Day	17% 25% 32% 20% 5% 1	540
	21st to end	Day	17% 29% 38% 11% 4 1	594
April	1st to 10th	Day	17% 25% 32% 14% 9% 2	540
	11th to 20th	Day	19% 29% 36% 10% 5% 1	532
	21st to end	Day	20% 29% 28% 15% 7% 1	540
May	1st to 10th	Day	19% 26% 33% 16% 5% 1	543
	11th to 20th	Day	17% 20% 35% 18% 8% 2	568
	21st to end	Day	15% 21% 28% 22% 11% 3	617
June	1st to 10th	Day	7% 19% 36% 25% 11% 2	643
	11th to 20th	Day	10% 21% 35% 21% 11% 3	776
	21st to end	Day	9% 19% 37% 27% 7% 1	570
July	1st to 10th	Day	8% 12% 33% 32% 12% 4	566
	11th to 20th	Day	6% 7% 34% 34% 15% 5%	564
	21st to end	Day	7% 6% 25% 36% 20% 5%	619
August	1st to 10th	Day	7% 10% 35% 31% 14% 3	567
	11th to 20th	Day	6% 9% 34% 33% 14% 5%	557
	21st to end	Day	7% 9% 33% 29% 16% 6%	627
September	1st to 10th	Day	7% 15% 28% 28% 15% 7%	570
	11th to 20th	Day	10% 18% 31% 24% 14% 4	543
	21st to end	Day	8% 15% 28% 29% 14% 5%	530
October	1st to 10th	Day	14% 19% 27% 21% 13% 6%	404
	11th to 20th	Day	14% 20% 28% 22% 15% 2	330
	21st to end	Day	12% 23% 30% 22% 11% 1	363
November	1st to 10th	Day	14% 27% 23% 21% 13% 1	330
	11th to 20th	Day	12% 19% 37% 20% 8% 4	330
	21st to end	Day	11% 20% 31% 24% 12% 2	330
December	1st to 10th	Day	13% 18% 33% 24% 9% 3	330
	11th to 20th	Day	9% 25% 32% 25% 8% 1	330
	21st to end	Day	18% 23% 32% 19% 7% 1	363
January	1st to 10th	Night	8% 18% 29% 27% 15% 4	840
	11th to 20th	Night	9% 18% 28% 30% 13% 3	840
	21st to end	Night	8% 21% 27% 29% 12% 2	924
February	1st to 10th	Night	9% 25% 31% 23% 9% 3	840
	11th to 20th	Night	7% 25% 31% 27% 8% 2	824
	21st to end	Night	9% 23% 34% 26% 7% 1	692
March	1st to 10th	Night	6% 20% 30% 31% 11% 2	840
	11th to 20th	Night	8% 16% 27% 32% 16% 2	840
	21st to end	Night	8% 23% 31% 27% 9% 2	924
April	1st to 10th	Night	11% 17% 31% 28% 11% 1	793
	11th to 20th	Night	11% 20% 34% 25% 8% 1	623
	21st to end	Night	8% 23% 31% 24% 12% 2	630
May	1st to 10th	Night	10% 18% 28% 30% 13% 2	630
	11th to 20th	Night	9% 11% 26% 32% 19% 3	621
	21st to end	Night	9% 14% 24% 30% 20% 2	683
June	1st to 10th	Night	7% 10% 27% 33% 21% 3	630
	11th to 20th	Night	6% 17% 29% 34% 13% 2	630
	21st to end	Night	4 9% 27% 37% 21% 3	630
July	1st to 10th	Night	5% 6% 20% 31% 33% 5%	615
	11th to 20th	Night	5% 5% 16% 38% 32% 5%	612
	21st to end	Night	7% 3 9% 40% 37% 5%	690
August	1st to 10th	Night	5% 5% 16% 41% 30% 3	627
	11th to 20th	Night	6% 3 15% 41% 31% 4	624
	21st to end	Night	5% 4 16% 37% 34% 4	693
September	1st to 10th	Night	5% 4 18% 37% 31% 6%	730
	11th to 20th	Night	4 5% 19% 39% 25% 8%	812
	21st to end	Night	7% 9% 19% 31% 27% 9%	800
October	1st to 10th	Night	7% 11% 23% 35% 22% 3	800
	11th to 20th	Night	6% 16% 22% 30% 22% 4	800
	21st to end	Night	7% 16% 23% 32% 17% 4	880
November	1st to 10th	Night	7% 14% 25% 32% 18% 4	820
	11th to 20th	Night	7% 19% 27% 30% 13% 4	840
	21st to end	Night	9% 18% 23% 30% 16% 4	980
December	1st to 10th	Night	10% 18% 30% 28% 12% 2	1050
	11th to 20th	Night	8% 19% 30% 31% 11% 1	1050
	21st to end	Night	13% 19% 30% 29% 8% 1	966

Page generated at 2026-09-11 02:11:57. Version ac07

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