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 2025-05-11.

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%	117921
	Night	2 5% 2 7% 5% 4 4 4 6% 7% 54%	119954
Transparency	Day	31% 3 9% 23% 22% 11%	117686
	Night	26% 3 10% 26% 23% 11%	119778
Seeing	Day	12% 20% 32% 23% 10% 3	15580
	Night	7% 15% 25% 31% 18% 3	26100

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 5% 11% 6% 6% 5% 5% 7% 10% 42%	4098
	11th to 20th	Day	1 5% 3 11% 9% 7% 5% 4 6% 6% 42%	4100
	21st to end	Day	2 8% 5% 10% 4 3 4 3 4 7% 53%	4510
February	1st to 10th	Day	1 9% 4 11% 6% 5% 4 4 6% 7% 44%	1800
	11th to 20th	Day	3 11% 5% 10% 4 3 4 5% 7% 8% 41%	1800
	21st to end	Day	2 10% 4 10% 6% 5% 4 4 5% 6% 43%	1650
March	1st to 10th	Day	1 10% 6% 11% 5% 4 4 3 6% 7% 42%	4927
	11th to 20th	Day	2 12% 4 14% 5% 4 5% 4 5% 6% 39%	5000
	21st to end	Day	2 14% 5% 12% 6% 6% 7% 4 5% 5% 32%	5486
April	1st to 10th	Day	3 9% 3 8% 6% 5% 6% 4 6% 7% 43%	2245
	11th to 20th	Day	4 9% 2 9% 6% 6% 5% 4 5% 6% 43%	2451
	21st to end	Day	5% 10% 3 7% 5% 5% 4 3 6% 7% 45%	2600
May	1st to 10th	Day	5% 9% 5% 8% 5% 5% 5% 5% 6% 6% 41%	4240
	11th to 20th	Day	4 6% 2 5% 5% 5% 5% 5% 7% 8% 47%	4073
	21st to end	Day	5% 8% 2 6% 5% 5% 5% 4 6% 8% 46%	4477
June	1st to 10th	Day	4 5% 1 5% 4 4 5% 4 6% 8% 54%	2536
	11th to 20th	Day	5% 4 2 5% 3 3 4 3 4 6% 61%	2657
	21st to end	Day	3 4 1 4 4 4 4 3 5% 6% 63%	2470
July	1st to 10th	Day	3 3 1 3 3 3 4 3 4 4 70%	4110
	11th to 20th	Day	4 4 2 6% 6% 7% 6% 6% 9% 8% 42%	4110
	21st to end	Day	3 4 1 5% 5% 5% 5% 5% 7% 7% 52%	4454
August	1st to 10th	Day	4 4 2 5% 5% 5% 7% 5% 8% 8% 48%	4092
	11th to 20th	Day	3 2 1 5% 5% 6% 6% 5% 6% 7% 55%	4028
	21st to end	Day	3 3 1 5% 4 5% 5% 4 6% 7% 57%	4407
September	1st to 10th	Day	4 4 2 5% 4 4 4 3 5% 6% 59%	2186
	11th to 20th	Day	5% 4 1 5% 4 4 3 3 5% 6% 60%	2090
	21st to end	Day	5% 5% 2 4 3 2 2 2 5% 5% 65%	2090
October	1st to 10th	Day	5% 5% 1 3 3 3 3 3 3 4 67%	3280
	11th to 20th	Day	8% 6% 2 5% 3 4 3 3 4 8% 55%	3150
	21st to end	Day	3 5% 2 5% 2 3 4 3 4 5% 63%	3438
November	1st to 10th	Day	3 7% 2 6% 4 3 3 4 6% 7% 54%	1831
	11th to 20th	Day	2 5% 2 5% 3 3 5% 4 7% 7% 58%	1800
	21st to end	Day	3 6% 4 7% 5% 3 4 4 6% 7% 52%	1643
December	1st to 10th	Day	1 4 2 6% 4 4 3 3 5% 9% 61%	2620
	11th to 20th	Day	1 5% 2 7% 4 4 5% 5% 8% 12% 47%	3026
	21st to end	Day	1 6% 4 11% 6% 6% 6% 5% 8% 8% 39%	4446
January	1st to 10th	Night	1 4 3 16% 8% 5% 5% 3 6% 8% 41%	5867
	11th to 20th	Night	3 2 13% 9% 7% 5% 4 7% 8% 42%	5880
	21st to end	Night	1 7% 4 11% 5% 3 3 3 5% 7% 52%	6468
February	1st to 10th	Night	1 6% 3 7% 5% 6% 5% 5% 6% 9% 48%	2600
	11th to 20th	Night	1 6% 3 8% 5% 5% 5% 5% 7% 9% 47%	2484
	21st to end	Night	2 5% 3 6% 5% 4 5% 6% 7% 7% 49%	1980
March	1st to 10th	Night	1 7% 4 9% 5% 4 5% 4 6% 7% 49%	4967
	11th to 20th	Night	1 8% 3 12% 6% 6% 6% 4 6% 8% 40%	5000
	21st to end	Night	1 7% 3 10% 5% 4 4 4 6% 7% 48%	5489
April	1st to 10th	Night	2 6% 2 6% 5% 5% 5% 4 6% 7% 53%	2155
	11th to 20th	Night	3 6% 3 7% 4 4 4 4 6% 8% 51%	1894
	21st to end	Night	3 6% 2 5% 4 4 4 4 7% 9% 52%	1800
May	1st to 10th	Night	3 8% 2 9% 6% 5% 5% 4 7% 8% 44%	2950
	11th to 20th	Night	2 4 2 5% 4 4 4 4 5% 6% 59%	2838
	21st to end	Night	4 5% 1 5% 3 3 4 3 5% 8% 58%	3110
June	1st to 10th	Night	4 4 1 3 3 4 3 5% 7% 9% 56%	1633
	11th to 20th	Night	3 3 1 4 3 3 4 3 4 5% 66%	1520
	21st to end	Night	2 1 1 3 3 4 5% 4 5% 6% 67%	1699
July	1st to 10th	Night	2 2 1 4 3 3 4 3 3 4 73%	2860
	11th to 20th	Night	3 4 2 5% 4 4 5% 5% 9% 10% 48%	2860
	21st to end	Night	3 2 2 6% 4 4 6% 6% 6% 8% 54%	3109
August	1st to 10th	Night	3 4 1 5% 4 5% 5% 5% 6% 9% 54%	2847
	11th to 20th	Night	3 3 2 6% 4 4 5% 4 6% 7% 56%	2811
	21st to end	Night	2 2 1 5% 4 3 3 3 4 6% 66%	3260
September	1st to 10th	Night	3 3 1 3 2 2 3 3 5% 7% 67%	1990
	11th to 20th	Night	3 2 1 3 3 4 3 3 4 7% 67%	2090
	21st to end	Night	5% 3 1 4 2 3 2 2 4 5% 69%	2090
October	1st to 10th	Night	3 3 1 3 2 2 2 3 4 6% 72%	3693
	11th to 20th	Night	3 4 2 5% 3 3 4 4 6% 7% 61%	3778
	21st to end	Night	3 5% 2 4 3 3 3 2 5% 8% 63%	4120
November	1st to 10th	Night	2 5% 2 5% 4 3 4 4 5% 7% 58%	2468
	11th to 20th	Night	1 4 1 5% 4 4 4 4 7% 8% 59%	2600
	21st to end	Night	2 6% 2 7% 5% 4 4 3 6% 8% 54%	2733
December	1st to 10th	Night	1 4 2 6% 4 3 3 3 5% 7% 63%	4570
	11th to 20th	Night	1 5% 2 6% 5% 5% 4 4 7% 9% 52%	5181
	21st to end	Night	2 8% 3 9% 7% 5% 5% 5% 7% 9% 42%	6560

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	32% 5% 16% 28% 15% 3	4099
	11th to 20th	Day	33% 4 14% 23% 22% 5%	4100
	21st to end	Day	30% 3 13% 21% 27% 6%	4510
February	1st to 10th	Day	36% 6% 19% 21% 14% 5%	1800
	11th to 20th	Day	36% 4 16% 25% 17% 2	1809
	21st to end	Day	38% 3 10% 28% 16% 4	1650
March	1st to 10th	Day	39% 2 7% 26% 19% 8%	4927
	11th to 20th	Day	45% 2 10% 26% 15% 2	5000
	21st to end	Day	50% 3 13% 24% 10% 1	5486
April	1st to 10th	Day	37% 4 11% 25% 19% 4	2245
	11th to 20th	Day	39% 3 9% 26% 20% 3	2454
	21st to end	Day	36% 3 8% 32% 20% 1	2600
May	1st to 10th	Day	36% 3 5% 24% 27% 5%	4240
	11th to 20th	Day	34% 3 4 28% 29% 2	4076
	21st to end	Day	35% 3 5% 25% 28% 4	4477
June	1st to 10th	Day	27% 3 6% 22% 33% 9%	2536
	11th to 20th	Day	25% 3 4 15% 31% 21%	2657
	21st to end	Day	22% 3 2 14% 27% 32%	2470
July	1st to 10th	Day	18% 4 2 7% 11% 58%	4046
	11th to 20th	Day	33% 6% 4 15% 22% 21%	4041
	21st to end	Day	28% 4 6% 14% 18% 29%	4314
August	1st to 10th	Day	30% 5% 9% 24% 18% 16%	4078
	11th to 20th	Day	27% 4 9% 13% 29% 18%	4067
	21st to end	Day	26% 4 6% 17% 22% 25%	4406
September	1st to 10th	Day	26% 4 6% 14% 27% 24%	2186
	11th to 20th	Day	27% 3 7% 17% 26% 20%	2090
	21st to end	Day	22% 3 4 20% 37% 14%	2090
October	1st to 10th	Day	23% 2 4 15% 40% 18%	3280
	11th to 20th	Day	30% 2 4 29% 30% 5%	3150
	21st to end	Day	22% 2 8% 35% 28% 5%	3438
November	1st to 10th	Day	27% 4 12% 27% 23% 6%	1831
	11th to 20th	Day	22% 4 17% 31% 23% 3	1800
	21st to end	Day	28% 3 12% 29% 22% 6%	1643
December	1st to 10th	Day	20% 4 13% 35% 24% 4	2620
	11th to 20th	Day	26% 3 21% 31% 18% 1	3024
	21st to end	Day	38% 4 14% 19% 18% 7%	4446
January	1st to 10th	Night	33% 3 14% 25% 20% 4	5867
	11th to 20th	Night	30% 3 15% 25% 22% 5%	5880
	21st to end	Night	30% 2 12% 24% 26% 7%	6468
February	1st to 10th	Night	28% 6% 20% 28% 15% 4	2600
	11th to 20th	Night	28% 5% 12% 28% 23% 4	2485
	21st to end	Night	26% 4 13% 30% 20% 7%	1980
March	1st to 10th	Night	32% 2 9% 31% 20% 7%	4967
	11th to 20th	Night	42% 2 8% 30% 15% 3	5000
	21st to end	Night	31% 2 17% 31% 18% 1	5489
April	1st to 10th	Night	26% 5% 13% 26% 22% 7%	2155
	11th to 20th	Night	28% 4 10% 31% 24% 4	1894
	21st to end	Night	25% 2 12% 36% 22% 2	1800
May	1st to 10th	Night	32% 2 6% 26% 28% 6%	2950
	11th to 20th	Night	26% 3 6% 32% 30% 4	2839
	21st to end	Night	25% 3 7% 31% 29% 5%	3110
June	1st to 10th	Night	23% 3 7% 28% 29% 10%	1633
	11th to 20th	Night	20% 3 5% 17% 31% 24%	1520
	21st to end	Night	17% 3 3 12% 27% 37%	1699
July	1st to 10th	Night	16% 3 3 8% 13% 57%	2815
	11th to 20th	Night	27% 4 6% 17% 24% 23%	2806
	21st to end	Night	26% 4 8% 18% 16% 28%	3011
August	1st to 10th	Night	27% 3 9% 24% 19% 19%	2838
	11th to 20th	Night	27% 3 9% 17% 22% 22%	2838
	21st to end	Night	19% 5% 5% 16% 29% 26%	3260
September	1st to 10th	Night	18% 3 7% 17% 29% 26%	1990
	11th to 20th	Night	19% 2 8% 22% 25% 23%	2090
	21st to end	Night	19% 2 3 19% 38% 19%	2090
October	1st to 10th	Night	15% 2 4 17% 36% 25%	3693
	11th to 20th	Night	22% 2 6% 33% 30% 7%	3778
	21st to end	Night	21% 2 7% 35% 31% 4	4120
November	1st to 10th	Night	23% 4 11% 31% 24% 8%	2468
	11th to 20th	Night	19% 3 15% 35% 24% 4	2600
	21st to end	Night	25% 3 11% 27% 25% 8%	2733
December	1st to 10th	Night	20% 3 12% 36% 25% 5%	4570
	11th to 20th	Night	25% 3 17% 37% 16% 2	5182
	21st to end	Night	34% 4 15% 26% 15% 6%	6560

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	18% 22% 30% 22% 6% 2	300
	11th to 20th	Day	20% 23% 24% 25% 6% 2	300
	21st to end	Day	11% 28% 32% 19% 9% 1	330
February	1st to 10th	Day	18% 35% 30% 11% 6%	300
	11th to 20th	Day	18% 32% 30% 14% 5% 1	345
	21st to end	Day	15% 32% 36% 14% 3	414
March	1st to 10th	Day	15% 27% 35% 17% 5%	500
	11th to 20th	Day	16% 24% 33% 21% 5% 1	500
	21st to end	Day	17% 29% 38% 12% 4 1	550
April	1st to 10th	Day	17% 26% 32% 14% 9% 2	500
	11th to 20th	Day	18% 29% 37% 11% 5% 1	492
	21st to end	Day	19% 28% 28% 16% 7% 1	500
May	1st to 10th	Day	19% 26% 34% 15% 5% 1	503
	11th to 20th	Day	15% 19% 35% 19% 9% 2	489
	21st to end	Day	14% 20% 29% 22% 12% 3	529
June	1st to 10th	Day	7% 17% 37% 26% 11% 2	556
	11th to 20th	Day	11% 19% 34% 22% 11% 3	677
	21st to end	Day	6% 18% 39% 29% 8% 1	490
July	1st to 10th	Day	8% 11% 30% 35% 12% 4	486
	11th to 20th	Day	5% 7% 33% 36% 14% 4	484
	21st to end	Day	6% 5% 25% 39% 20% 5%	531
August	1st to 10th	Day	7% 6% 36% 33% 15% 3	487
	11th to 20th	Day	5% 9% 34% 33% 14% 4	477
	21st to end	Day	6% 10% 33% 29% 17% 5%	539
September	1st to 10th	Day	6% 13% 28% 29% 16% 8%	490
	11th to 20th	Day	10% 17% 30% 24% 15% 4	490
	21st to end	Day	9% 16% 28% 28% 14% 5%	490
October	1st to 10th	Day	14% 17% 26% 22% 14% 6%	371
	11th to 20th	Day	11% 19% 28% 23% 16% 3	300
	21st to end	Day	12% 24% 31% 22% 11% 1	330
November	1st to 10th	Day	15% 27% 23% 21% 13% 1	300
	11th to 20th	Day	12% 19% 37% 21% 8% 4	300
	21st to end	Day	11% 19% 31% 25% 12% 2	300
December	1st to 10th	Day	11% 17% 33% 26% 10% 3	300
	11th to 20th	Day	8% 26% 30% 27% 8% 1	300
	21st to end	Day	17% 24% 33% 19% 6% 1	330
January	1st to 10th	Night	8% 17% 29% 27% 16% 4	800
	11th to 20th	Night	9% 18% 28% 30% 12% 3	800
	21st to end	Night	8% 21% 26% 30% 13% 3	880
February	1st to 10th	Night	9% 25% 32% 23% 8% 4	800
	11th to 20th	Night	6% 26% 29% 28% 9% 2	784
	21st to end	Night	9% 22% 34% 27% 7% 1	660
March	1st to 10th	Night	6% 20% 30% 32% 11% 2	800
	11th to 20th	Night	7% 16% 27% 33% 16% 2	800
	21st to end	Night	8% 23% 30% 27% 9% 2	880
April	1st to 10th	Night	11% 17% 32% 28% 11% 1	755
	11th to 20th	Night	10% 21% 34% 25% 9% 1	593
	21st to end	Night	7% 23% 30% 25% 13% 2	600
May	1st to 10th	Night	10% 18% 27% 30% 13% 2	600
	11th to 20th	Night	7% 10% 26% 33% 20% 3	563
	21st to end	Night	9% 14% 24% 29% 21% 2	617
June	1st to 10th	Night	7% 11% 27% 31% 22% 3	570
	11th to 20th	Night	6% 17% 26% 35% 14% 2	570
	21st to end	Night	3 8% 26% 39% 22% 3	570
July	1st to 10th	Night	5% 6% 20% 28% 35% 6%	555
	11th to 20th	Night	5% 4 15% 38% 33% 5%	552
	21st to end	Night	6% 3 9% 38% 38% 6%	624
August	1st to 10th	Night	5% 4 14% 41% 32% 4	567
	11th to 20th	Night	6% 3 16% 39% 32% 4	564
	21st to end	Night	5% 4 16% 37% 33% 5%	627
September	1st to 10th	Night	5% 4 17% 35% 33% 6%	660
	11th to 20th	Night	5% 5% 19% 38% 26% 8%	760
	21st to end	Night	7% 9% 18% 30% 27% 9%	760
October	1st to 10th	Night	6% 11% 23% 34% 23% 3	760
	11th to 20th	Night	5% 15% 22% 31% 23% 4	760
	21st to end	Night	7% 16% 23% 32% 17% 5%	836
November	1st to 10th	Night	7% 14% 25% 32% 18% 4	780
	11th to 20th	Night	7% 19% 26% 30% 14% 4	800
	21st to end	Night	9% 18% 23% 30% 16% 4	933
December	1st to 10th	Night	9% 17% 30% 30% 12% 2	1000
	11th to 20th	Night	8% 20% 29% 32% 11% 1	1000
	21st to end	Night	12% 19% 29% 30% 8% 1	920

Page generated at 2025-05-08 07:34:01. Version ac07

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