Douthat State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Douthat State Park clear sky chart from 2005-11-06 to 2024-11-11.

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	14% 7% 2 7% 5% 5% 5% 4 6% 8% 38%	100788
	Night	14% 7% 2 6% 4 4 4 4 6% 7% 41%	98280
Transparency	Day	41% 8% 12% 21% 15% 4	104437
	Night	39% 7% 13% 22% 16% 3	102770
Seeing	Day	23% 12% 24% 22% 13% 5%	15062
	Night	19% 11% 20% 32% 17% 2	25209

By Month

Percentage Cloud Cover SE (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	16% 8% 3 7% 5% 5% 4 4 5% 6% 39%	2836
	11th to 20th	Day	13% 8% 4 10% 8% 6% 4 3 5% 6% 34%	2840
	21st to end	Day	19% 10% 3 7% 5% 4 3 3 4 5% 37%	3124
February	1st to 10th	Day	13% 8% 3 7% 5% 5% 5% 4 5% 7% 38%	1710
	11th to 20th	Day	16% 7% 3 7% 5% 5% 4 4 5% 7% 37%	1673
	21st to end	Day	18% 9% 3 6% 4 5% 4 4 5% 5% 38%	1648
March	1st to 10th	Day	21% 9% 3 6% 4 4 4 3 5% 7% 34%	3435
	11th to 20th	Day	10% 6% 2 6% 4 4 4 4 5% 8% 48%	3480
	21st to end	Day	16% 9% 3 8% 5% 4 4 3 4 6% 37%	3815
April	1st to 10th	Day	12% 7% 2 6% 5% 5% 4 4 5% 7% 43%	2176
	11th to 20th	Day	14% 5% 2 6% 5% 4 5% 4 5% 6% 43%	2254
	21st to end	Day	17% 7% 2 6% 5% 4 4 3 6% 5% 40%	2408
May	1st to 10th	Day	17% 7% 3 8% 6% 5% 6% 4 6% 7% 29%	4082
	11th to 20th	Day	22% 7% 3 7% 5% 5% 4 4 6% 7% 30%	4081
	21st to end	Day	10% 5% 2 6% 4 6% 6% 5% 8% 9% 39%	4476
June	1st to 10th	Day	12% 4 2 6% 6% 5% 6% 5% 7% 9% 38%	2497
	11th to 20th	Day	9% 6% 3 7% 6% 5% 6% 5% 8% 10% 36%	2599
	21st to end	Day	9% 5% 2 6% 5% 6% 6% 5% 8% 11% 37%	2470
July	1st to 10th	Day	7% 5% 2 7% 5% 6% 6% 5% 8% 9% 41%	4120
	11th to 20th	Day	9% 5% 2 6% 6% 6% 6% 5% 8% 11% 36%	4120
	21st to end	Day	14% 8% 3 9% 7% 6% 6% 5% 7% 8% 26%	4466
August	1st to 10th	Day	14% 6% 2 7% 6% 6% 6% 5% 8% 10% 31%	4104
	11th to 20th	Day	9% 5% 2 7% 6% 6% 7% 5% 9% 10% 35%	4044
	21st to end	Day	9% 4 2 5% 4 5% 5% 4 7% 10% 46%	4217
September	1st to 10th	Day	13% 6% 2 6% 3 5% 4 4 4 6% 45%	2275
	11th to 20th	Day	15% 6% 2 6% 4 4 5% 3 5% 8% 40%	2090
	21st to end	Day	23% 7% 3 7% 4 4 4 3 5% 6% 34%	2087
October	1st to 10th	Day	16% 6% 2 5% 4 4 3 3 4 7% 45%	1900
	11th to 20th	Day	15% 5% 2 6% 3 4 3 2 5% 6% 48%	1900
	21st to end	Day	15% 6% 2 6% 4 4 4 3 4 5% 48%	2090
November	1st to 10th	Day	11% 6% 2 5% 4 3 3 3 5% 5% 52%	1957
	11th to 20th	Day	14% 6% 2 5% 4 3 4 3 5% 6% 48%	1743
	21st to end	Day	15% 6% 2 5% 4 3 3 4 4 6% 48%	1544
December	1st to 10th	Day	17% 8% 3 8% 5% 5% 5% 3 6% 7% 34%	1520
	11th to 20th	Day	15% 6% 2 5% 4 3 3 3 4 7% 48%	1910
	21st to end	Day	19% 7% 3 8% 6% 5% 5% 5% 6% 6% 30%	3097
January	1st to 10th	Night	12% 9% 2 7% 4 5% 6% 4 6% 6% 38%	4109
	11th to 20th	Night	15% 9% 3 6% 4 3 3 3 5% 6% 43%	4120
	21st to end	Night	21% 10% 3 6% 3 3 3 3 4 5% 39%	4532
February	1st to 10th	Night	13% 8% 3 7% 5% 4 4 3 7% 7% 40%	2470
	11th to 20th	Night	17% 9% 2 7% 4 4 4 4 5% 6% 38%	2389
	21st to end	Night	15% 7% 3 6% 5% 4 5% 4 6% 6% 38%	1804
March	1st to 10th	Night	22% 10% 3 7% 4 4 5% 4 5% 5% 33%	3418
	11th to 20th	Night	10% 5% 3 7% 4 4 4 4 6% 6% 47%	3480
	21st to end	Night	16% 6% 2 5% 3 3 3 3 5% 7% 46%	3817
April	1st to 10th	Night	13% 7% 2 7% 4 4 4 4 5% 7% 42%	2002
	11th to 20th	Night	12% 5% 2 4 4 4 4 5% 6% 8% 46%	1875
	21st to end	Night	15% 4 2 5% 5% 4 4 4 6% 7% 43%	1786
May	1st to 10th	Night	18% 9% 3 8% 5% 4 4 4 5% 8% 33%	2813
	11th to 20th	Night	24% 9% 2 7% 4 4 3 3 5% 6% 32%	2812
	21st to end	Night	10% 5% 2 6% 4 4 5% 5% 7% 9% 43%	3079
June	1st to 10th	Night	10% 5% 3 6% 3 3 5% 5% 7% 11% 43%	1663
	11th to 20th	Night	11% 4 2 6% 4 5% 4 4 7% 10% 44%	1559
	21st to end	Night	9% 5% 1 5% 4 5% 5% 4 7% 10% 45%	1710
July	1st to 10th	Night	6% 4 2 6% 5% 4 5% 5% 9% 12% 43%	2840
	11th to 20th	Night	8% 5% 2 7% 4 4 5% 4 8% 12% 41%	2840
	21st to end	Night	11% 10% 3 10% 6% 5% 5% 4 7% 9% 30%	3087
August	1st to 10th	Night	16% 6% 2 6% 5% 5% 5% 5% 7% 9% 33%	2825
	11th to 20th	Night	11% 6% 2 7% 6% 6% 5% 5% 7% 8% 38%	2785
	21st to end	Night	9% 5% 2 5% 4 4 5% 4 6% 9% 47%	3406
September	1st to 10th	Night	12% 5% 2 7% 4 4 4 4 5% 6% 47%	1901
	11th to 20th	Night	16% 7% 3 5% 4 4 4 3 4 7% 43%	2090
	21st to end	Night	22% 6% 2 5% 4 4 4 3 6% 5% 37%	2091
October	1st to 10th	Night	16% 6% 2 5% 4 4 3 3 5% 6% 46%	2280
	11th to 20th	Night	13% 7% 2 6% 5% 3 4 3 5% 5% 47%	2280
	21st to end	Night	14% 4 1 5% 3 3 3 3 5% 6% 51%	2508
November	1st to 10th	Night	12% 8% 3 6% 3 3 3 2 4 6% 50%	2341
	11th to 20th	Night	14% 5% 1 5% 4 3 4 4 5% 7% 49%	2442
	21st to end	Night	13% 5% 2 5% 4 3 4 3 5% 6% 48%	2631
December	1st to 10th	Night	18% 8% 2 7% 4 4 4 2 5% 6% 40%	2660
	11th to 20th	Night	14% 8% 2 6% 5% 4 5% 4 6% 6% 40%	3285
	21st to end	Night	17% 6% 2 8% 6% 5% 6% 4 6% 7% 33%	4550

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	44% 5% 7% 23% 16% 4	2837
	11th to 20th	Day	48% 7% 9% 16% 16% 4	2840
	21st to end	Day	49% 5% 8% 21% 15% 2	3124
February	1st to 10th	Day	45% 7% 10% 20% 15% 3	1710
	11th to 20th	Day	45% 5% 11% 20% 16% 4	1682
	21st to end	Day	47% 6% 10% 17% 15% 5%	1648
March	1st to 10th	Day	48% 5% 11% 20% 12% 4	3435
	11th to 20th	Day	34% 7% 10% 24% 20% 6%	3480
	21st to end	Day	48% 7% 9% 19% 14% 3	3815
April	1st to 10th	Day	39% 7% 12% 20% 16% 6%	2176
	11th to 20th	Day	38% 7% 12% 20% 18% 4	2254
	21st to end	Day	45% 7% 11% 22% 12% 4	2408
May	1st to 10th	Day	51% 9% 11% 19% 9% 1	4120
	11th to 20th	Day	51% 9% 11% 20% 8% 1	4085
	21st to end	Day	35% 11% 17% 20% 15% 3	4489
June	1st to 10th	Day	39% 10% 15% 23% 13% 1	2497
	11th to 20th	Day	40% 11% 15% 19% 15% 1	2599
	21st to end	Day	38% 10% 14% 24% 12% 2	2470
July	1st to 10th	Day	36% 11% 20% 19% 9% 5%	4055
	11th to 20th	Day	37% 11% 17% 25% 10% 1	4051
	21st to end	Day	52% 9% 13% 18% 8% 1	4324
August	1st to 10th	Day	44% 11% 17% 21% 8%	4091
	11th to 20th	Day	38% 10% 13% 27% 12% 1	4083
	21st to end	Day	32% 8% 19% 25% 14% 1	4217
September	1st to 10th	Day	38% 8% 12% 18% 19% 4	2275
	11th to 20th	Day	41% 7% 9% 23% 17% 3	2090
	21st to end	Day	49% 6% 10% 18% 16% 2	2087
October	1st to 10th	Day	33% 5% 8% 20% 26% 8%	3160
	11th to 20th	Day	27% 4 10% 24% 21% 14%	3140
	21st to end	Day	25% 4 9% 30% 19% 12%	3428
November	1st to 10th	Day	34% 5% 9% 22% 26% 4	1957
	11th to 20th	Day	36% 5% 9% 21% 22% 6%	1743
	21st to end	Day	37% 5% 11% 25% 20% 3	1544
December	1st to 10th	Day	48% 6% 13% 16% 14% 3	1520
	11th to 20th	Day	35% 5% 11% 24% 20% 5%	1906
	21st to end	Day	48% 8% 11% 19% 11% 2	3097
January	1st to 10th	Night	40% 8% 11% 21% 18% 3	4109
	11th to 20th	Night	41% 5% 10% 23% 16% 5%	4120
	21st to end	Night	47% 4 6% 25% 14% 3	4532
February	1st to 10th	Night	40% 6% 12% 23% 17% 2	2470
	11th to 20th	Night	46% 5% 9% 19% 17% 5%	2391
	21st to end	Night	44% 7% 11% 21% 11% 5%	1804
March	1st to 10th	Night	51% 6% 10% 17% 13% 2	3418
	11th to 20th	Night	34% 6% 10% 23% 24% 3	3480
	21st to end	Night	37% 6% 13% 22% 18% 4	3817
April	1st to 10th	Night	39% 8% 14% 19% 17% 4	2002
	11th to 20th	Night	35% 6% 14% 20% 19% 5%	1875
	21st to end	Night	38% 6% 13% 26% 15% 2	1786
May	1st to 10th	Night	48% 9% 13% 18% 9% 2	2840
	11th to 20th	Night	51% 8% 11% 21% 8% 1	2813
	21st to end	Night	33% 11% 18% 25% 8% 4	3087
June	1st to 10th	Night	34% 11% 15% 25% 14% 1	1663
	11th to 20th	Night	34% 10% 18% 23% 13% 2	1559
	21st to end	Night	32% 11% 16% 24% 15% 2	1710
July	1st to 10th	Night	32% 13% 20% 20% 12% 3	2795
	11th to 20th	Night	35% 10% 20% 26% 9% 1	2786
	21st to end	Night	49% 10% 14% 20% 8%	2988
August	1st to 10th	Night	45% 10% 18% 22% 5%	2814
	11th to 20th	Night	41% 8% 15% 22% 13%	2812
	21st to end	Night	32% 8% 17% 30% 11% 2	3406
September	1st to 10th	Night	36% 8% 15% 18% 18% 5%	1901
	11th to 20th	Night	40% 6% 11% 23% 17% 2	2090
	21st to end	Night	46% 7% 10% 19% 15% 2	2091
October	1st to 10th	Night	36% 7% 10% 20% 22% 5%	3800
	11th to 20th	Night	27% 6% 9% 21% 27% 10%	3779
	21st to end	Night	21% 4 11% 29% 25% 10%	4120
November	1st to 10th	Night	36% 5% 9% 21% 23% 6%	2341
	11th to 20th	Night	34% 5% 10% 24% 21% 5%	2442
	21st to end	Night	37% 5% 10% 25% 19% 4	2631
December	1st to 10th	Night	45% 5% 10% 24% 13% 3	2660
	11th to 20th	Night	42% 5% 11% 21% 18% 2	3288
	21st to end	Night	44% 7% 16% 17% 14% 1	4550

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	39% 18% 27% 11% 3 1	270
	11th to 20th	Day	42% 21% 23% 12% 2	270
	21st to end	Day	39% 21% 24% 12% 4	297
February	1st to 10th	Day	32% 22% 30% 11% 4 1	270
	11th to 20th	Day	44% 20% 26% 9% 1	270
	21st to end	Day	38% 20% 28% 12% 2	303
March	1st to 10th	Day	30% 22% 23% 19% 6%	460
	11th to 20th	Day	31% 23% 23% 19% 3 1	460
	21st to end	Day	28% 21% 25% 19% 7% 1	506
April	1st to 10th	Day	27% 23% 23% 19% 8% 1	460
	11th to 20th	Day	23% 17% 28% 19% 10% 3	452
	21st to end	Day	28% 17% 26% 17% 8% 4	460
May	1st to 10th	Day	25% 17% 27% 18% 9% 3	463
	11th to 20th	Day	25% 12% 24% 20% 14% 5%	487
	21st to end	Day	17% 10% 24% 24% 17% 9%	529
June	1st to 10th	Day	16% 9% 29% 23% 16% 7%	490
	11th to 20th	Day	14% 7% 28% 24% 19% 8%	490
	21st to end	Day	12% 9% 30% 27% 17% 6%	490
July	1st to 10th	Day	11% 4 21% 28% 22% 13%	485
	11th to 20th	Day	7% 3 21% 32% 25% 11%	484
	21st to end	Day	14% 5% 24% 27% 21% 10%	532
August	1st to 10th	Day	17% 6% 24% 20% 21% 12%	486
	11th to 20th	Day	14% 5% 22% 27% 21% 11%	479
	21st to end	Day	13% 3 16% 28% 25% 15%	539
September	1st to 10th	Day	16% 4 19% 26% 23% 12%	490
	11th to 20th	Day	19% 4 17% 28% 24% 8%	490
	21st to end	Day	31% 8% 20% 24% 14% 4	490
October	1st to 10th	Day	21% 8% 20% 29% 19% 3	490
	11th to 20th	Day	20% 13% 22% 28% 15% 2	490
	21st to end	Day	22% 14% 26% 26% 11% 2	539
November	1st to 10th	Day	19% 12% 27% 28% 11% 3	495
	11th to 20th	Day	29% 15% 25% 22% 8% 1	303
	21st to end	Day	27% 18% 25% 21% 7% 2	192
December	1st to 10th	Day	29% 21% 30% 15% 4 1	180
	11th to 20th	Day	32% 17% 27% 16% 7% 1	180
	21st to end	Day	30% 19% 29% 16% 6%	291
January	1st to 10th	Night	25% 19% 28% 24% 3	760
	11th to 20th	Night	28% 16% 23% 30% 3	760
	21st to end	Night	23% 20% 30% 25% 2	836
February	1st to 10th	Night	21% 19% 25% 32% 3	760
	11th to 20th	Night	29% 22% 26% 21% 1	743
	21st to end	Night	25% 17% 32% 24% 2	628
March	1st to 10th	Night	22% 15% 29% 28% 5%	760
	11th to 20th	Night	27% 16% 26% 23% 7% 1	760
	21st to end	Night	21% 15% 28% 29% 7% 1	836
April	1st to 10th	Night	21% 18% 25% 30% 6%	760
	11th to 20th	Night	20% 13% 25% 29% 13% 1	751
	21st to end	Night	19% 12% 22% 36% 11% 1	646
May	1st to 10th	Night	20% 8% 22% 36% 13% 2	570
	11th to 20th	Night	21% 8% 17% 35% 17% 1	561
	21st to end	Night	16% 3 13% 35% 29% 4	617
June	1st to 10th	Night	11% 3 13% 43% 28% 2	523
	11th to 20th	Night	10% 3 10% 40% 34% 3	419
	21st to end	Night	10% 3 12% 44% 27% 4	570
July	1st to 10th	Night	12% 2 9% 37% 35% 5%	555
	11th to 20th	Night	7% 1 8% 33% 48% 4	552
	21st to end	Night	9% 3 9% 38% 37% 4	624
August	1st to 10th	Night	16% 3 8% 36% 34% 3	567
	11th to 20th	Night	15% 2 7% 34% 37% 4	564
	21st to end	Night	12% 2 8% 35% 38% 6%	792
September	1st to 10th	Night	14% 4 9% 33% 34% 6%	760
	11th to 20th	Night	19% 4 10% 29% 33% 5%	760
	21st to end	Night	25% 5% 14% 31% 23% 2	760
October	1st to 10th	Night	18% 7% 16% 30% 25% 3	760
	11th to 20th	Night	19% 10% 20% 32% 17% 1	760
	21st to end	Night	18% 9% 21% 37% 14% 2	836
November	1st to 10th	Night	17% 9% 22% 36% 15% 2	780
	11th to 20th	Night	22% 13% 20% 34% 11% 1	763
	21st to end	Night	20% 13% 22% 34% 10% 1	760
December	1st to 10th	Night	26% 15% 25% 27% 6%	760
	11th to 20th	Night	19% 15% 24% 37% 5%	760
	21st to end	Night	23% 14% 24% 36% 4	836

Page generated at 2024-11-08 06:44:50. Version ac07

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