Hualapai Mountain County Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hualapai Mountain County Park clear sky chart from 2005-11-06 to 2025-07-21.

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	2 3 1 3 3 3 3 3 5% 6% 67%	124448
	Night	2 3 1 3 3 3 3 3 4 6% 70%	123683
Transparency	Day	17% 3 5% 13% 27% 36%	124216
	Night	15% 2 5% 14% 28% 35%	123503
Seeing	Day	8% 15% 31% 30% 13% 3	16133
	Night	5% 8% 20% 33% 28% 7%	26339

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	2 4 2 4 3 3 3 3 5% 5% 65%	4098
	11th to 20th	Day	1 2 1 4 3 3 3 3 3 5% 73%	4100
	21st to end	Day	7% 7% 2 5% 4 4 4 3 4 5% 54%	4510
February	1st to 10th	Day	3 5% 1 4 4 3 3 2 4 6% 64%	1987
	11th to 20th	Day	4 5% 2 4 4 4 4 3 5% 5% 61%	1950
	21st to end	Day	5% 5% 2 4 4 3 3 2 4 6% 60%	1650
March	1st to 10th	Day	2 6% 2 4 3 3 4 3 5% 6% 64%	4689
	11th to 20th	Day	4 7% 2 6% 6% 5% 4 4 5% 6% 52%	5000
	21st to end	Day	2 2 1 4 4 4 4 4 6% 8% 60%	5486
April	1st to 10th	Day	2 3 1 4 4 3 3 3 5% 7% 65%	2220
	11th to 20th	Day	2 3 1 3 2 3 3 2 3 4 74%	2380
	21st to end	Day	1 2 1 3 3 3 3 2 3 6% 73%	2600
May	1st to 10th	Day	4 3 1 4 3 3 3 3 4 5% 68%	5880
	11th to 20th	Day	1 1 1 3 2 3 3 2 4 5% 76%	5841
	21st to end	Day	1 1 1 2 1 2 2 1 3 4 82%	6423
June	1st to 10th	Day	1 2 1 2 2 2 2 2 3 5% 79%	2600
	11th to 20th	Day	1 1 2 1 1 2 1 2 3 86%	2600
	21st to end	Day	1 1 2 2 2 3 3 3 3 79%	2600
July	1st to 10th	Day	1 1 1 2 2 2 2 2 3 3 81%	4240
	11th to 20th	Day	2 2 1 3 4 4 6% 5% 8% 10% 56%	4240
	21st to end	Day	2 3 1 4 3 5% 5% 5% 6% 7% 58%	4455
August	1st to 10th	Day	3 3 2 5% 5% 5% 6% 5% 7% 9% 51%	4092
	11th to 20th	Day	1 2 1 3 3 3 4 3 5% 6% 69%	3914
	21st to end	Day	2 2 1 3 3 3 4 3 5% 7% 69%	4180
September	1st to 10th	Day	3 3 1 4 4 4 5% 3 6% 9% 58%	2104
	11th to 20th	Day	1 1 1 2 1 3 2 2 3 4 79%	2090
	21st to end	Day	2 1 1 3 2 3 3 2 4 5% 75%	2090
October	1st to 10th	Day	2 2 1 3 3 3 3 3 4 4 73%	3490
	11th to 20th	Day	1 1 1 2 1 2 2 2 3 5% 80%	3255
	21st to end	Day	1 1 1 2 3 3 2 4 5% 78%	3438
November	1st to 10th	Day	1 3 1 2 3 3 2 3 3 6% 74%	1777
	11th to 20th	Day	1 2 1 3 1 3 3 2 4 5% 74%	1800
	21st to end	Day	3 3 1 3 3 3 3 4 5% 6% 64%	1800
December	1st to 10th	Day	2 3 1 3 3 3 4 4 5% 7% 66%	2950
	11th to 20th	Day	3 3 1 4 3 3 4 5% 7% 11% 56%	3409
	21st to end	Day	5% 4 1 4 4 4 4 5% 7% 9% 54%	4510
January	1st to 10th	Night	2 3 1 4 3 3 3 3 5% 7% 67%	5867
	11th to 20th	Night	2 2 1 4 3 3 3 3 4 6% 70%	5880
	21st to end	Night	6% 5% 2 4 4 3 3 3 4 7% 58%	6468
February	1st to 10th	Night	4 4 1 4 3 3 3 3 4 6% 64%	2410
	11th to 20th	Night	3 5% 2 4 3 3 3 3 5% 7% 63%	2338
	21st to end	Night	5% 6% 2 4 3 2 4 3 5% 7% 60%	1980
March	1st to 10th	Night	3 4 2 4 3 3 3 4 6% 6% 64%	5205
	11th to 20th	Night	3 6% 2 5% 5% 5% 5% 4 6% 7% 52%	5000
	21st to end	Night	2 2 1 3 3 4 3 4 7% 7% 64%	5489
April	1st to 10th	Night	2 2 1 4 4 3 3 2 3 6% 68%	2175
	11th to 20th	Night	1 2 1 4 3 3 2 2 3 4 75%	1965
	21st to end	Night	1 2 1 2 2 2 2 2 3 7% 75%	1800
May	1st to 10th	Night	3 3 1 4 2 3 3 2 4 4 71%	4100
	11th to 20th	Night	1 2 1 3 2 2 2 2 3 4 79%	4074
	21st to end	Night	1 1 2 1 1 2 1 3 5% 83%	4474
June	1st to 10th	Night	1 1 2 2 2 2 2 4 5% 80%	1800
	11th to 20th	Night	1 1 1 2 1 2 2 2 2 4 84%	1800
	21st to end	Night	1 1 1 3 3 2 2 2 3 4 80%	1800
July	1st to 10th	Night	1 1 1 2 1 1 2 2 2 4 83%	2950
	11th to 20th	Night	2 2 1 4 3 3 4 3 6% 7% 65%	2950
	21st to end	Night	2 3 1 4 3 3 3 3 6% 9% 63%	3109
August	1st to 10th	Night	2 2 1 3 2 3 4 4 6% 11% 62%	2847
	11th to 20th	Night	1 1 1 3 2 2 3 3 5% 7% 73%	2926
	21st to end	Night	2 2 1 2 1 2 2 2 4 6% 77%	3498
September	1st to 10th	Night	2 2 1 5% 3 3 4 3 5% 5% 68%	2074
	11th to 20th	Night	2 1 2 2 1 2 2 3 5% 82%	2090
	21st to end	Night	1 1 1 2 2 2 2 2 3 4 81%	2090
October	1st to 10th	Night	2 1 2 2 1 2 1 3 4 82%	3490
	11th to 20th	Night	1 1 1 1 2 2 2 4 6% 80%	3675
	21st to end	Night	1 1 2 2 3 3 2 3 5% 79%	4120
November	1st to 10th	Night	1 2 1 2 3 2 3 3 4 5% 74%	2520
	11th to 20th	Night	2 1 1 3 2 2 3 2 3 6% 75%	2600
	21st to end	Night	3 3 1 4 3 3 3 3 4 5% 67%	2600
December	1st to 10th	Night	3 3 1 3 3 3 3 3 5% 6% 68%	4240
	11th to 20th	Night	3 3 1 3 3 4 5% 3 5% 8% 61%	4811
	21st to end	Night	4 3 1 4 4 3 4 3 6% 8% 60%	6468

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	18% 3 5% 19% 36% 18%	4099
	11th to 20th	Day	14% 3 4 19% 22% 38%	4100
	21st to end	Day	31% 3 5% 9% 30% 23%	4510
February	1st to 10th	Day	22% 2 6% 14% 27% 29%	1987
	11th to 20th	Day	24% 3 5% 14% 27% 27%	1960
	21st to end	Day	25% 2 7% 14% 27% 25%	1650
March	1st to 10th	Day	20% 3 5% 15% 31% 26%	4689
	11th to 20th	Day	27% 4 7% 19% 26% 16%	5000
	21st to end	Day	18% 3 8% 21% 34% 16%	5486
April	1st to 10th	Day	16% 3 8% 13% 29% 30%	2220
	11th to 20th	Day	13% 2 5% 10% 30% 40%	2383
	21st to end	Day	12% 2 5% 11% 36% 34%	2600
May	1st to 10th	Day	20% 2 4 12% 31% 33%	5880
	11th to 20th	Day	9% 2 5% 8% 30% 47%	5844
	21st to end	Day	9% 1 2 4 27% 57%	6424
June	1st to 10th	Day	9% 1 4 7% 26% 52%	2600
	11th to 20th	Day	6% 1 3 4 15% 72%	2600
	21st to end	Day	9% 1 4 6% 12% 67%	2600
July	1st to 10th	Day	9% 2 3 5% 9% 71%	4176
	11th to 20th	Day	22% 4 6% 15% 28% 26%	4171
	21st to end	Day	22% 5% 8% 15% 16% 34%	4315
August	1st to 10th	Day	29% 3 11% 20% 18% 20%	4078
	11th to 20th	Day	17% 3 7% 13% 30% 31%	3953
	21st to end	Day	14% 4 5% 12% 25% 41%	4179
September	1st to 10th	Day	20% 4 7% 12% 24% 32%	2104
	11th to 20th	Day	10% 3 5% 8% 26% 49%	2090
	21st to end	Day	12% 2 4 10% 25% 46%	2090
October	1st to 10th	Day	14% 3 3 7% 17% 57%	3490
	11th to 20th	Day	7% 2 2 10% 35% 44%	3255
	21st to end	Day	8% 1 3 8% 28% 52%	3438
November	1st to 10th	Day	12% 2 5% 14% 34% 32%	1777
	11th to 20th	Day	12% 2 5% 16% 26% 39%	1800
	21st to end	Day	19% 3 6% 13% 29% 29%	1800
December	1st to 10th	Day	18% 3 4 14% 30% 31%	2950
	11th to 20th	Day	18% 3 7% 18% 35% 19%	3408
	21st to end	Day	22% 4 8% 26% 28% 11%	4510
January	1st to 10th	Night	17% 3 5% 18% 36% 21%	5867
	11th to 20th	Night	14% 4 6% 19% 22% 35%	5880
	21st to end	Night	26% 3 5% 13% 26% 27%	6468
February	1st to 10th	Night	21% 3 8% 15% 25% 29%	2410
	11th to 20th	Night	21% 2 6% 15% 30% 26%	2339
	21st to end	Night	23% 3 6% 12% 30% 27%	1980
March	1st to 10th	Night	18% 3 6% 18% 28% 26%	5205
	11th to 20th	Night	27% 3 6% 21% 28% 15%	5000
	21st to end	Night	15% 2 8% 20% 38% 16%	5489
April	1st to 10th	Night	17% 3 7% 13% 35% 26%	2175
	11th to 20th	Night	14% 2 4 10% 32% 38%	1965
	21st to end	Night	11% 2 5% 11% 37% 35%	1800
May	1st to 10th	Night	17% 1 4 13% 31% 34%	4097
	11th to 20th	Night	9% 1 4 6% 32% 48%	4075
	21st to end	Night	8% 2 4 28% 58%	4474
June	1st to 10th	Night	8% 2 3 7% 28% 52%	1800
	11th to 20th	Night	6% 1 3 5% 16% 69%	1800
	21st to end	Night	9% 1 4 5% 12% 69%	1800
July	1st to 10th	Night	8% 2 2 5% 9% 74%	2905
	11th to 20th	Night	17% 3 6% 15% 30% 28%	2896
	21st to end	Night	15% 5% 8% 20% 18% 34%	3011
August	1st to 10th	Night	17% 2 8% 29% 22% 21%	2838
	11th to 20th	Night	12% 2 9% 16% 28% 34%	2953
	21st to end	Night	11% 2 3 15% 23% 46%	3498
September	1st to 10th	Night	18% 3 7% 14% 22% 36%	2074
	11th to 20th	Night	8% 2 4 10% 25% 51%	2090
	21st to end	Night	8% 2 5% 8% 24% 52%	2090
October	1st to 10th	Night	9% 1 3 8% 16% 63%	3490
	11th to 20th	Night	8% 1 2 8% 37% 44%	3675
	21st to end	Night	8% 2 3 8% 24% 55%	4120
November	1st to 10th	Night	13% 2 4 14% 34% 33%	2520
	11th to 20th	Night	12% 2 5% 13% 31% 37%	2600
	21st to end	Night	19% 2 6% 13% 27% 33%	2600
December	1st to 10th	Night	16% 2 4 13% 31% 34%	4240
	11th to 20th	Night	17% 3 6% 15% 36% 23%	4811
	21st to end	Night	20% 4 8% 23% 33% 12%	6468

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	17% 18% 27% 25% 12% 1	300
	11th to 20th	Day	14% 14% 30% 27% 11% 3	300
	21st to end	Day	11% 17% 27% 27% 13% 5%	330
February	1st to 10th	Day	13% 24% 32% 20% 9% 3	487
	11th to 20th	Day	14% 24% 34% 20% 6% 1	495
	21st to end	Day	17% 24% 35% 18% 6% 1	414
March	1st to 10th	Day	16% 26% 33% 19% 6%	500
	11th to 20th	Day	15% 22% 32% 21% 7% 2	500
	21st to end	Day	13% 28% 32% 19% 7%	550
April	1st to 10th	Day	10% 22% 33% 22% 10% 2	500
	11th to 20th	Day	12% 30% 34% 15% 7% 2	492
	21st to end	Day	8% 27% 30% 22% 10% 3	500
May	1st to 10th	Day	9% 22% 36% 23% 8% 2	503
	11th to 20th	Day	6% 19% 40% 21% 11% 2	528
	21st to end	Day	6% 18% 40% 26% 8% 3	573
June	1st to 10th	Day	3 12% 37% 35% 11% 2	530
	11th to 20th	Day	2 13% 41% 28% 11% 5%	530
	21st to end	Day	3 11% 37% 35% 12% 3	530
July	1st to 10th	Day	1 5% 35% 42% 13% 4	526
	11th to 20th	Day	3 2 26% 44% 18% 6%	524
	21st to end	Day	3 3 15% 49% 23% 7%	532
August	1st to 10th	Day	3 3 25% 43% 19% 6%	487
	11th to 20th	Day	3 4 26% 41% 19% 7%	477
	21st to end	Day	4 3 24% 43% 19% 7%	539
September	1st to 10th	Day	4 5% 26% 41% 18% 6%	490
	11th to 20th	Day	4 8% 38% 32% 15% 3	490
	21st to end	Day	3 13% 29% 35% 15% 4	490
October	1st to 10th	Day	4 15% 34% 29% 13% 4	490
	11th to 20th	Day	5% 15% 28% 33% 16% 4	366
	21st to end	Day	3 17% 27% 29% 19% 5%	330
November	1st to 10th	Day	8% 14% 31% 28% 18% 2	300
	11th to 20th	Day	8% 13% 26% 28% 21% 3	300
	21st to end	Day	11% 17% 22% 29% 19% 2	300
December	1st to 10th	Day	6% 16% 24% 36% 16% 2	300
	11th to 20th	Day	4 18% 28% 33% 14% 3	300
	21st to end	Day	14% 17% 33% 25% 9% 2	330
January	1st to 10th	Night	8% 10% 22% 32% 21% 7%	800
	11th to 20th	Night	6% 9% 24% 34% 20% 8%	800
	21st to end	Night	10% 11% 24% 31% 19% 5%	880
February	1st to 10th	Night	7% 14% 23% 30% 21% 6%	800
	11th to 20th	Night	6% 14% 25% 34% 17% 3	784
	21st to end	Night	12% 13% 25% 31% 15% 4	660
March	1st to 10th	Night	6% 16% 27% 32% 18% 2	800
	11th to 20th	Night	8% 11% 22% 29% 22% 8%	800
	21st to end	Night	5% 13% 25% 35% 18% 4	880
April	1st to 10th	Night	5% 13% 24% 31% 22% 4	800
	11th to 20th	Night	4 16% 26% 32% 18% 4	777
	21st to end	Night	2 11% 27% 34% 21% 5%	600
May	1st to 10th	Night	4 11% 28% 32% 22% 3	600
	11th to 20th	Night	3 10% 25% 30% 28% 6%	591
	21st to end	Night	3 8% 28% 36% 22% 4	650
June	1st to 10th	Night	2 6% 19% 42% 28% 4	600
	11th to 20th	Night	2 7% 25% 32% 31% 4	600
	21st to end	Night	1 4 16% 38% 36% 5%	600
July	1st to 10th	Night	3 1 15% 34% 41% 7%	585
	11th to 20th	Night	3 2 6% 35% 45% 9%	582
	21st to end	Night	3 1 6% 25% 56% 9%	624
August	1st to 10th	Night	3 1 8% 31% 49% 8%	567
	11th to 20th	Night	3 1 7% 30% 48% 11%	627
	21st to end	Night	4 2 8% 27% 44% 16%	836
September	1st to 10th	Night	4 3 8% 30% 43% 12%	760
	11th to 20th	Night	3 2 16% 35% 33% 11%	760
	21st to end	Night	2 4 16% 33% 34% 11%	760
October	1st to 10th	Night	3 6% 18% 40% 28% 4	760
	11th to 20th	Night	3 4 18% 38% 30% 8%	760
	21st to end	Night	3 9% 17% 31% 27% 12%	836
November	1st to 10th	Night	3 8% 18% 34% 30% 7%	780
	11th to 20th	Night	4 7% 21% 33% 26% 9%	800
	21st to end	Night	6% 12% 20% 30% 24% 7%	800
December	1st to 10th	Night	8% 7% 20% 35% 24% 6%	800
	11th to 20th	Night	9% 8% 20% 34% 24% 5%	800
	21st to end	Night	9% 11% 26% 33% 16% 6%	880

Page generated at 2025-07-17 22:10:01. Version ac07

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