Datil Well Recreation Area Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Datil Well Recreation Area Campground clear sky chart from 2005-11-06 to 2025-02-25.

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 4 2 5% 4 4 4 4 5% 7% 59%	112527
	Night	2 3 1 4 3 3 4 3 5% 7% 63%	115020
Transparency	Day	24% 3 6% 17% 29% 21%	112290
	Night	21% 3 7% 19% 30% 20%	114846
Seeing	Day	9% 15% 25% 26% 19% 6%	14753
	Night	5% 10% 26% 34% 22% 3	25288

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% 2 6% 3 3 3 3 4 6% 63%	4098
	11th to 20th	Day	1 3 1 3 2 2 3 2 4 6% 73%	4100
	21st to end	Day	3 7% 3 5% 3 3 4 3 4 6% 60%	4510
February	1st to 10th	Day	1 4 2 5% 3 3 3 4 6% 6% 63%	1800
	11th to 20th	Day	2 5% 2 5% 3 3 4 3 4 6% 64%	1877
	21st to end	Day	2 6% 2 4 2 2 3 4 5% 7% 65%	1689
March	1st to 10th	Day	1 3 2 4 3 4 5% 5% 7% 7% 59%	3444
	11th to 20th	Day	7% 12% 3 6% 3 4 3 4 5% 7% 47%	3490
	21st to end	Day	1 4 2 4 4 3 4 4 6% 7% 60%	3825
April	1st to 10th	Day	2 3 1 3 3 3 4 4 5% 7% 65%	2251
	11th to 20th	Day	2 5% 1 4 3 3 3 3 4 7% 65%	2251
	21st to end	Day	2 4 2 4 3 3 3 3 4 6% 65%	2280
May	1st to 10th	Day	2 3 1 3 3 2 3 3 5% 5% 72%	3800
	11th to 20th	Day	3 5% 2 5% 4 4 5% 3 5% 5% 59%	4035
	21st to end	Day	2 2 1 3 2 2 2 2 3 5% 77%	4477
June	1st to 10th	Day	3 4 1 4 4 4 4 4 5% 7% 60%	2470
	11th to 20th	Day	3 2 1 4 4 3 3 3 5% 6% 68%	2470
	21st to end	Day	4 4 2 7% 5% 5% 5% 4 6% 8% 49%	2470
July	1st to 10th	Day	4 4 2 6% 5% 5% 5% 4 5% 7% 54%	4110
	11th to 20th	Day	5% 4 2 8% 7% 7% 8% 6% 7% 8% 37%	4110
	21st to end	Day	6% 6% 3 8% 7% 8% 8% 7% 9% 10% 29%	4454
August	1st to 10th	Day	5% 5% 2 7% 6% 7% 8% 5% 9% 10% 38%	4092
	11th to 20th	Day	4 4 2 6% 5% 5% 6% 6% 8% 9% 44%	3758
	21st to end	Day	6% 5% 2 8% 7% 7% 7% 6% 8% 9% 35%	4180
September	1st to 10th	Day	10% 5% 2 7% 5% 5% 5% 4 6% 6% 45%	2280
	11th to 20th	Day	7% 4 2 6% 4 4 5% 3 4 6% 54%	2243
	21st to end	Day	4 4 1 4 4 4 4 2 4 6% 64%	2015
October	1st to 10th	Day	4 3 1 4 3 4 3 3 4 5% 66%	3170
	11th to 20th	Day	5% 4 2 4 3 3 3 2 4 6% 64%	3150
	21st to end	Day	1 1 1 2 1 1 2 2 3 4 83%	3438
November	1st to 10th	Day	2 2 1 3 2 2 2 2 5% 6% 72%	1959
	11th to 20th	Day	2 3 1 4 3 3 3 2 4 6% 71%	2000
	21st to end	Day	3 4 2 4 3 4 3 3 5% 6% 64%	1830
December	1st to 10th	Day	2 2 1 2 2 1 2 2 3 5% 77%	2620
	11th to 20th	Day	2 3 2 4 4 3 3 3 4 6% 66%	3271
	21st to end	Day	1 3 1 3 3 3 4 3 5% 6% 69%	4510
January	1st to 10th	Night	1 6% 3 7% 4 3 3 3 5% 7% 59%	5867
	11th to 20th	Night	1 2 1 2 2 1 3 2 3 5% 78%	5880
	21st to end	Night	2 6% 2 5% 3 4 4 3 5% 7% 59%	6468
February	1st to 10th	Night	1 4 2 3 3 3 4 3 5% 6% 67%	2600
	11th to 20th	Night	2 4 1 3 3 3 4 3 5% 6% 64%	2409
	21st to end	Night	2 3 2 3 2 3 3 3 5% 7% 68%	1856
March	1st to 10th	Night	1 3 2 4 2 2 3 2 4 6% 71%	3430
	11th to 20th	Night	8% 10% 2 4 3 3 4 2 4 6% 54%	3490
	21st to end	Night	1 3 1 3 2 3 3 3 6% 8% 67%	3828
April	1st to 10th	Night	1 2 1 3 2 3 2 4 5% 7% 69%	1929
	11th to 20th	Night	2 3 1 3 3 2 3 3 4 5% 71%	1877
	21st to end	Night	2 3 1 3 2 3 3 3 4 7% 70%	1900
May	1st to 10th	Night	2 2 1 3 2 2 2 2 3 4 78%	3170
	11th to 20th	Night	3 3 1 4 3 3 4 3 4 6% 65%	2865
	21st to end	Night	1 2 1 2 1 1 1 1 2 5% 83%	3110
June	1st to 10th	Night	4 4 2 3 4 3 3 3 4 8% 64%	1710
	11th to 20th	Night	2 2 1 3 2 2 3 3 5% 6% 71%	1710
	21st to end	Night	3 4 2 5% 5% 5% 6% 6% 7% 7% 51%	1710
July	1st to 10th	Night	2 3 1 5% 5% 5% 5% 4 6% 8% 55%	2860
	11th to 20th	Night	3 3 2 6% 5% 5% 6% 6% 10% 12% 40%	2860
	21st to end	Night	4 5% 2 7% 6% 7% 7% 6% 10% 12% 35%	3109
August	1st to 10th	Night	2 3 2 6% 6% 7% 7% 6% 10% 13% 39%	2847
	11th to 20th	Night	4 5% 2 7% 6% 6% 7% 6% 9% 10% 40%	3079
	21st to end	Night	4 4 2 7% 7% 7% 8% 7% 11% 12% 31%	3487
September	1st to 10th	Night	7% 4 2 6% 6% 4 6% 4 7% 8% 47%	1900
	11th to 20th	Night	6% 3 1 5% 4 4 4 3 5% 7% 58%	1932
	21st to end	Night	4 3 1 3 3 3 4 3 5% 5% 66%	2163
October	1st to 10th	Night	3 3 1 4 3 3 3 2 4 5% 68%	3800
	11th to 20th	Night	5% 3 1 4 3 3 4 3 5% 7% 64%	3778
	21st to end	Night	1 1 2 2 2 3 3 4 5% 77%	4120
November	1st to 10th	Night	2 3 2 2 2 2 2 4 6% 75%	2340
	11th to 20th	Night	1 1 1 3 2 1 2 2 4 6% 76%	2400
	21st to end	Night	4 5% 1 3 3 2 3 3 4 7% 65%	2540
December	1st to 10th	Night	2 2 1 3 2 2 3 2 4 7% 73%	4570
	11th to 20th	Night	1 2 1 3 3 3 3 3 6% 8% 65%	4958
	21st to end	Night	2 3 1 3 3 3 3 3 5% 6% 68%	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	24% 2 3 20% 40% 11%	4099
	11th to 20th	Day	14% 1 7% 22% 31% 25%	4100
	21st to end	Day	26% 2 3 15% 28% 26%	4510
February	1st to 10th	Day	20% 2 6% 18% 31% 23%	1800
	11th to 20th	Day	22% 2 3 22% 31% 19%	1886
	21st to end	Day	21% 2 2 13% 33% 29%	1689
March	1st to 10th	Day	23% 2 3 11% 40% 22%	3444
	11th to 20th	Day	37% 1 2 19% 28% 13%	3490
	21st to end	Day	24% 1 3 18% 41% 14%	3825
April	1st to 10th	Day	17% 2 3 16% 38% 24%	2251
	11th to 20th	Day	21% 2 2 12% 33% 31%	2254
	21st to end	Day	20% 2 3 16% 37% 21%	2280
May	1st to 10th	Day	15% 1 2 9% 38% 35%	3800
	11th to 20th	Day	27% 1 3 11% 33% 25%	4038
	21st to end	Day	13% 1 2 6% 21% 57%	4477
June	1st to 10th	Day	23% 2 3 15% 26% 30%	2470
	11th to 20th	Day	17% 1 3 7% 24% 47%	2470
	21st to end	Day	31% 4 7% 14% 24% 21%	2470
July	1st to 10th	Day	29% 5% 8% 10% 16% 31%	4046
	11th to 20th	Day	37% 7% 14% 25% 12% 4	4041
	21st to end	Day	42% 10% 21% 20% 7% 1	4314
August	1st to 10th	Day	34% 9% 19% 21% 12% 4	4078
	11th to 20th	Day	29% 6% 13% 22% 23% 7%	3794
	21st to end	Day	41% 8% 14% 17% 16% 4	4179
September	1st to 10th	Day	36% 4 9% 16% 22% 13%	2280
	11th to 20th	Day	31% 3 5% 17% 25% 19%	2243
	21st to end	Day	23% 2 5% 17% 29% 24%	2015
October	1st to 10th	Day	17% 3 6% 14% 28% 33%	3170
	11th to 20th	Day	19% 3 5% 14% 37% 23%	3150
	21st to end	Day	8% 1 3 14% 36% 38%	3438
November	1st to 10th	Day	13% 2 3 22% 37% 23%	1959
	11th to 20th	Day	16% 1 4 18% 38% 24%	2000
	21st to end	Day	23% 2 4 16% 34% 21%	1830
December	1st to 10th	Day	12% 1 4 26% 38% 18%	2620
	11th to 20th	Day	22% 2 5% 16% 41% 15%	3270
	21st to end	Day	18% 2 5% 24% 32% 19%	4510
January	1st to 10th	Night	28% 2 4 19% 37% 10%	5867
	11th to 20th	Night	12% 1 6% 22% 38% 20%	5880
	21st to end	Night	28% 2 4 16% 25% 25%	6468
February	1st to 10th	Night	18% 2 7% 22% 29% 22%	2600
	11th to 20th	Night	20% 2 5% 25% 29% 19%	2410
	21st to end	Night	18% 1 4 19% 32% 25%	1856
March	1st to 10th	Night	18% 2 2 17% 44% 16%	3430
	11th to 20th	Night	34% 1 3 20% 30% 12%	3490
	21st to end	Night	19% 1 3 28% 39% 10%	3828
April	1st to 10th	Night	15% 2 4 22% 37% 21%	1929
	11th to 20th	Night	18% 2 3 14% 36% 28%	1877
	21st to end	Night	16% 2 3 19% 39% 21%	1900
May	1st to 10th	Night	12% 1 3 9% 49% 27%	3170
	11th to 20th	Night	20% 2 6% 17% 34% 20%	2866
	21st to end	Night	8% 1 3 8% 22% 57%	3110
June	1st to 10th	Night	21% 2 5% 17% 26% 29%	1710
	11th to 20th	Night	15% 2 3 10% 25% 45%	1710
	21st to end	Night	29% 4 11% 13% 18% 24%	1710
July	1st to 10th	Night	27% 6% 10% 13% 14% 30%	2815
	11th to 20th	Night	30% 9% 17% 26% 13% 4	2806
	21st to end	Night	35% 9% 28% 21% 4 1	3011
August	1st to 10th	Night	31% 9% 24% 22% 10% 4	2838
	11th to 20th	Night	34% 10% 17% 20% 12% 7%	3109
	21st to end	Night	38% 10% 20% 17% 11% 3	3487
September	1st to 10th	Night	32% 4 13% 18% 20% 13%	1900
	11th to 20th	Night	25% 4 9% 18% 26% 18%	1932
	21st to end	Night	20% 3 4 18% 34% 21%	2163
October	1st to 10th	Night	18% 3 6% 14% 30% 28%	3800
	11th to 20th	Night	18% 4 7% 19% 30% 21%	3778
	21st to end	Night	10% 2 3 15% 39% 31%	4120
November	1st to 10th	Night	12% 2 2 25% 37% 22%	2340
	11th to 20th	Night	12% 1 4 22% 36% 25%	2400
	21st to end	Night	21% 2 4 21% 34% 19%	2540
December	1st to 10th	Night	14% 3 6% 28% 29% 20%	4570
	11th to 20th	Night	18% 2 5% 18% 40% 16%	4958
	21st to end	Night	20% 2 5% 23% 35% 16%	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	9% 22% 32% 26% 9% 2	300
	11th to 20th	Day	13% 18% 26% 27% 13% 3	300
	21st to end	Day	5% 20% 29% 25% 17% 2	330
February	1st to 10th	Day	6% 22% 32% 25% 13% 2	300
	11th to 20th	Day	12% 22% 35% 25% 7%	300
	21st to end	Day	15% 33% 25% 18% 6% 2	316
March	1st to 10th	Day	12% 29% 32% 17% 8% 1	460
	11th to 20th	Day	15% 25% 30% 18% 10% 2	460
	21st to end	Day	14% 35% 27% 17% 5% 1	506
April	1st to 10th	Day	9% 26% 33% 20% 10% 2	460
	11th to 20th	Day	15% 29% 31% 16% 7% 2	452
	21st to end	Day	11% 25% 34% 19% 8% 2	460
May	1st to 10th	Day	7% 23% 37% 25% 7% 1	463
	11th to 20th	Day	7% 16% 33% 25% 15% 4	488
	21st to end	Day	8% 18% 35% 27% 10% 1	529
June	1st to 10th	Day	6% 8% 32% 31% 19% 4	490
	11th to 20th	Day	6% 11% 27% 29% 21% 6%	490
	21st to end	Day	6% 5% 25% 33% 23% 7%	490
July	1st to 10th	Day	9% 1 14% 34% 34% 7%	486
	11th to 20th	Day	10% 1 11% 25% 35% 17%	484
	21st to end	Day	10% 1 9% 21% 37% 22%	531
August	1st to 10th	Day	10% 2 10% 27% 36% 16%	487
	11th to 20th	Day	8% 1 13% 29% 31% 17%	477
	21st to end	Day	12% 1 12% 28% 31% 15%	539
September	1st to 10th	Day	10% 3 12% 32% 32% 11%	490
	11th to 20th	Day	7% 5% 21% 34% 26% 7%	490
	21st to end	Day	5% 8% 23% 32% 24% 8%	415
October	1st to 10th	Day	7% 12% 22% 24% 26% 9%	300
	11th to 20th	Day	10% 8% 25% 28% 24% 6%	300
	21st to end	Day	8% 12% 19% 28% 26% 7%	330
November	1st to 10th	Day	7% 16% 31% 29% 14% 3	300
	11th to 20th	Day	5% 12% 21% 32% 25% 5%	300
	21st to end	Day	6% 24% 28% 22% 17% 4	300
December	1st to 10th	Day	7% 19% 26% 27% 18% 3	300
	11th to 20th	Day	7% 21% 27% 27% 15% 3	300
	21st to end	Day	13% 22% 31% 23% 9% 2	330
January	1st to 10th	Night	6% 13% 28% 34% 17% 3	800
	11th to 20th	Night	5% 14% 30% 34% 16% 2	800
	21st to end	Night	6% 13% 33% 30% 17% 2	880
February	1st to 10th	Night	4 16% 31% 35% 14% 1	800
	11th to 20th	Night	6% 15% 41% 30% 8% 1	784
	21st to end	Night	7% 20% 38% 29% 6%	646
March	1st to 10th	Night	4 19% 36% 31% 10% 1	760
	11th to 20th	Night	6% 16% 31% 32% 13% 1	760
	21st to end	Night	4 19% 35% 31% 9% 1	836
April	1st to 10th	Night	3 16% 42% 31% 8% 1	599
	11th to 20th	Night	4 21% 39% 28% 8%	563
	21st to end	Night	4 18% 42% 26% 10%	570
May	1st to 10th	Night	5% 12% 37% 38% 8%	570
	11th to 20th	Night	5% 8% 30% 39% 17% 1	561
	21st to end	Night	3 7% 37% 38% 13% 1	617
June	1st to 10th	Night	6% 5% 27% 46% 15% 1	570
	11th to 20th	Night	3 4 29% 47% 17%	570
	21st to end	Night	5% 2 19% 44% 28% 2	570
July	1st to 10th	Night	5% 1 11% 41% 37% 6%	555
	11th to 20th	Night	5% 5% 30% 53% 6%	552
	21st to end	Night	8% 7% 19% 55% 11%	624
August	1st to 10th	Night	4 1 7% 22% 52% 13%	567
	11th to 20th	Night	6% 1 6% 30% 50% 7%	564
	21st to end	Night	6% 1 7% 31% 46% 9%	627
September	1st to 10th	Night	8% 8% 37% 40% 5%	570
	11th to 20th	Night	6% 1 11% 45% 33% 4	602
	21st to end	Night	5% 2 18% 39% 33% 3	760
October	1st to 10th	Night	6% 4 24% 41% 22% 4	760
	11th to 20th	Night	5% 4 22% 45% 21% 3	760
	21st to end	Night	4 9% 22% 35% 25% 5%	836
November	1st to 10th	Night	4 8% 23% 38% 23% 3	780
	11th to 20th	Night	2 7% 28% 37% 22% 3	800
	21st to end	Night	7% 15% 24% 31% 20% 3	900
December	1st to 10th	Night	5% 13% 27% 38% 15% 2	1000
	11th to 20th	Night	6% 16% 31% 31% 15% 1	895
	21st to end	Night	5% 19% 30% 32% 12% 2	880

Page generated at 2025-02-22 04:51:35. Version ac07

Copyright © 2025 Attilla Danko.