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 2024-01-13.

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% 6% 3 6% 6% 4 5% 5% 6% 7% 39%	74457
	Night	14% 6% 3 5% 5% 3 5% 5% 6% 7% 42%	75237
Transparency	Day	42% 8% 12% 21% 15% 3	74178
	Night	39% 7% 13% 22% 16% 3	75035
Seeing	Day	23% 13% 24% 22% 14% 5%	13893
	Night	19% 11% 20% 32% 17% 2	24128

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	14% 9% 3 5% 6% 4 5% 4 4 6% 38%	1706
	11th to 20th	Day	18% 8% 5% 7% 6% 3 4 3 5% 7% 36%	1638
	21st to end	Day	16% 8% 3 6% 5% 3 4 3 4 6% 41%	1782
February	1st to 10th	Day	14% 8% 4 6% 7% 3 5% 5% 5% 7% 36%	1620
	11th to 20th	Day	16% 6% 4 6% 5% 4 5% 5% 5% 7% 37%	1583
	21st to end	Day	18% 9% 3 6% 4 3 5% 4 5% 5% 38%	1553
March	1st to 10th	Day	14% 5% 2 4 4 3 4 3 5% 6% 49%	1980
	11th to 20th	Day	17% 7% 3 7% 5% 3 4 5% 5% 7% 36%	1980
	21st to end	Day	18% 7% 3 7% 5% 3 5% 4 4 5% 38%	2178
April	1st to 10th	Day	12% 6% 3 5% 5% 3 4 5% 5% 7% 44%	2061
	11th to 20th	Day	14% 5% 2 5% 5% 3 5% 5% 5% 6% 44%	2134
	21st to end	Day	17% 7% 3 5% 6% 3 5% 4 6% 5% 40%	2281
May	1st to 10th	Day	15% 6% 3 7% 7% 4 6% 5% 6% 7% 34%	2340
	11th to 20th	Day	19% 7% 3 6% 6% 4 5% 5% 6% 7% 32%	2301
	21st to end	Day	14% 6% 3 6% 5% 4 7% 7% 7% 8% 35%	2531
June	1st to 10th	Day	13% 4 2 5% 6% 4 7% 6% 6% 8% 39%	2365
	11th to 20th	Day	10% 6% 3 6% 7% 4 6% 6% 7% 10% 35%	2463
	21st to end	Day	9% 4 3 6% 6% 5% 6% 6% 7% 11% 37%	2340
July	1st to 10th	Day	11% 6% 3 8% 6% 4 6% 6% 7% 9% 35%	2340
	11th to 20th	Day	6% 4 2 5% 7% 5% 7% 8% 9% 11% 35%	2340
	21st to end	Day	11% 6% 3 6% 8% 5% 7% 7% 8% 9% 31%	2547
August	1st to 10th	Day	13% 6% 2 6% 6% 5% 6% 6% 7% 10% 32%	2327
	11th to 20th	Day	14% 6% 3 7% 6% 5% 5% 6% 9% 9% 31%	2303
	21st to end	Day	12% 5% 2 5% 6% 4 5% 7% 8% 10% 35%	2399
September	1st to 10th	Day	14% 6% 3 5% 4 4 4 5% 5% 6% 44%	2156
	11th to 20th	Day	15% 6% 2 5% 5% 3 5% 4 5% 7% 42%	1980
	21st to end	Day	22% 6% 3 6% 5% 3 4 4 5% 6% 36%	1978
October	1st to 10th	Day	16% 6% 3 4 5% 3 4 4 4 7% 45%	1800
	11th to 20th	Day	16% 5% 3 5% 4 3 4 3 5% 7% 47%	1800
	21st to end	Day	16% 6% 2 5% 4 3 3 4 4 5% 47%	1980
November	1st to 10th	Day	11% 6% 3 5% 4 2 3 4 5% 5% 53%	1857
	11th to 20th	Day	15% 5% 2 5% 5% 2 4 3 5% 6% 48%	1743
	21st to end	Day	15% 5% 2 4 5% 2 3 5% 4 6% 48%	1544
December	1st to 10th	Day	17% 8% 3 7% 6% 3 5% 4 6% 7% 34%	1520
	11th to 20th	Day	16% 5% 2 4 4 2 3 3 4 7% 48%	1910
	21st to end	Day	19% 7% 3 7% 7% 4 5% 6% 6% 7% 30%	3097
January	1st to 10th	Night	14% 6% 2 5% 5% 3 5% 6% 6% 6% 41%	2459
	11th to 20th	Night	16% 8% 4 5% 4 4 4 4 6% 7% 38%	2378
	21st to end	Night	14% 7% 3 6% 5% 3 5% 5% 5% 6% 42%	2574
February	1st to 10th	Night	14% 7% 3 6% 5% 3 4 4 7% 8% 39%	2340
	11th to 20th	Night	17% 8% 2 6% 5% 3 4 5% 5% 6% 38%	2259
	21st to end	Night	16% 7% 4 6% 6% 3 4 5% 6% 6% 38%	1701
March	1st to 10th	Night	12% 5% 3 4 4 3 5% 5% 5% 6% 49%	1980
	11th to 20th	Night	17% 7% 3 6% 5% 3 5% 4 6% 7% 37%	1980
	21st to end	Night	15% 6% 3 5% 4 3 4 4 5% 6% 43%	2178
April	1st to 10th	Night	13% 6% 3 6% 5% 3 4 5% 5% 7% 43%	1897
	11th to 20th	Night	12% 5% 2 4 4 3 4 5% 6% 8% 47%	1775
	21st to end	Night	16% 4 2 5% 6% 3 4 5% 6% 7% 43%	1692
May	1st to 10th	Night	14% 7% 3 6% 5% 2 4 4 5% 8% 41%	1620
	11th to 20th	Night	19% 8% 2 6% 5% 3 4 4 5% 7% 35%	1592
	21st to end	Night	14% 5% 2 5% 4 3 5% 6% 7% 9% 39%	1744
June	1st to 10th	Night	10% 5% 3 5% 4 2 5% 6% 6% 11% 44%	1576
	11th to 20th	Night	11% 4 2 5% 5% 4 4 5% 6% 9% 44%	1476
	21st to end	Night	9% 3 2 4 4 4 5% 6% 7% 10% 46%	1620
July	1st to 10th	Night	9% 6% 2 5% 6% 3 6% 6% 7% 10% 41%	1620
	11th to 20th	Night	6% 3 2 5% 5% 3 5% 5% 8% 12% 47%	1620
	21st to end	Night	6% 5% 2 5% 6% 4 6% 5% 8% 11% 40%	1771
August	1st to 10th	Night	13% 6% 2 5% 5% 4 5% 7% 8% 8% 37%	1611
	11th to 20th	Night	12% 6% 3 5% 6% 3 5% 5% 6% 8% 41%	1598
	21st to end	Night	10% 5% 2 5% 6% 3 6% 6% 7% 10% 39%	1938
September	1st to 10th	Night	13% 5% 2 5% 5% 3 4 5% 6% 6% 47%	1800
	11th to 20th	Night	15% 6% 3 5% 4 3 4 4 4 7% 44%	1980
	21st to end	Night	20% 6% 3 5% 5% 3 4 4 5% 6% 39%	1980
October	1st to 10th	Night	15% 6% 2 4 4 3 4 4 5% 6% 46%	2160
	11th to 20th	Night	14% 7% 2 5% 5% 3 4 4 4 5% 46%	2160
	21st to end	Night	15% 4 2 5% 4 2 3 3 5% 6% 50%	2376
November	1st to 10th	Night	12% 7% 3 5% 4 2 3 3 3 6% 52%	2221
	11th to 20th	Night	14% 5% 2 4 4 2 4 5% 4 7% 50%	2435
	21st to end	Night	13% 5% 2 5% 5% 2 5% 4 5% 7% 48%	2631
December	1st to 10th	Night	18% 8% 3 6% 5% 3 5% 3 5% 5% 40%	2660
	11th to 20th	Night	14% 7% 3 5% 6% 3 5% 5% 6% 6% 40%	3285
	21st to end	Night	17% 5% 2 6% 7% 3 6% 6% 6% 7% 34%	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% 7% 9% 20% 16% 4	1707
	11th to 20th	Day	49% 5% 9% 20% 15% 1	1638
	21st to end	Day	44% 5% 10% 19% 18% 4	1782
February	1st to 10th	Day	46% 7% 11% 20% 14% 3	1620
	11th to 20th	Day	46% 5% 11% 20% 15% 3	1592
	21st to end	Day	47% 6% 10% 17% 16% 5%	1553
March	1st to 10th	Day	36% 5% 11% 23% 21% 4	1980
	11th to 20th	Day	47% 7% 10% 17% 15% 5%	1980
	21st to end	Day	47% 7% 10% 20% 13% 4	2178
April	1st to 10th	Day	38% 6% 12% 21% 16% 6%	2061
	11th to 20th	Day	39% 6% 12% 20% 18% 4	2134
	21st to end	Day	45% 7% 10% 21% 12% 4	2281
May	1st to 10th	Day	46% 9% 13% 19% 11% 2	2340
	11th to 20th	Day	48% 10% 13% 19% 7% 3	2305
	21st to end	Day	44% 11% 15% 21% 9% 1	2531
June	1st to 10th	Day	39% 10% 15% 23% 13% 1	2365
	11th to 20th	Day	41% 11% 15% 17% 15% 1	2463
	21st to end	Day	38% 10% 14% 24% 12% 2	2340
July	1st to 10th	Day	43% 10% 13% 18% 13% 3	2275
	11th to 20th	Day	36% 13% 17% 19% 13% 2	2271
	21st to end	Day	43% 10% 15% 20% 10% 1	2405
August	1st to 10th	Day	43% 11% 15% 21% 9%	2314
	11th to 20th	Day	44% 11% 14% 21% 9%	2303
	21st to end	Day	40% 10% 19% 18% 10% 2	2399
September	1st to 10th	Day	39% 8% 13% 19% 18% 4	2156
	11th to 20th	Day	41% 7% 9% 23% 17% 3	1980
	21st to end	Day	48% 6% 10% 18% 17% 2	1978
October	1st to 10th	Day	40% 6% 10% 25% 15% 5%	1800
	11th to 20th	Day	37% 5% 11% 24% 19% 3	1800
	21st to end	Day	39% 5% 7% 25% 19% 4	1980
November	1st to 10th	Day	33% 5% 9% 23% 26% 4	1857
	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% 7% 11% 20% 16% 5%	2459
	11th to 20th	Night	43% 6% 11% 22% 15% 3	2378
	21st to end	Night	41% 5% 9% 25% 17% 2	2574
February	1st to 10th	Night	41% 7% 13% 22% 16% 2	2340
	11th to 20th	Night	46% 6% 9% 19% 16% 5%	2261
	21st to end	Night	45% 6% 11% 21% 12% 5%	1701
March	1st to 10th	Night	34% 6% 12% 24% 20% 4	1980
	11th to 20th	Night	44% 7% 10% 20% 17% 2	1980
	21st to end	Night	40% 8% 12% 20% 15% 4	2178
April	1st to 10th	Night	38% 7% 14% 19% 17% 4	1897
	11th to 20th	Night	35% 6% 14% 20% 20% 5%	1775
	21st to end	Night	38% 6% 13% 26% 15% 2	1692
May	1st to 10th	Night	41% 8% 16% 19% 13% 3	1620
	11th to 20th	Night	47% 9% 14% 20% 9% 1	1593
	21st to end	Night	39% 10% 17% 26% 8% 1	1745
June	1st to 10th	Night	34% 11% 15% 25% 14% 1	1576
	11th to 20th	Night	35% 11% 18% 22% 13% 2	1476
	21st to end	Night	32% 12% 16% 23% 14% 2	1620
July	1st to 10th	Night	36% 12% 15% 20% 13% 3	1575
	11th to 20th	Night	28% 12% 19% 26% 14% 2	1566
	21st to end	Night	33% 11% 18% 25% 13%	1672
August	1st to 10th	Night	39% 11% 18% 23% 9%	1600
	11th to 20th	Night	40% 8% 15% 23% 12% 1	1598
	21st to end	Night	36% 11% 17% 22% 11% 3	1938
September	1st to 10th	Night	35% 9% 15% 19% 18% 4	1800
	11th to 20th	Night	39% 6% 11% 24% 17% 2	1980
	21st to end	Night	45% 7% 10% 19% 16% 2	1980
October	1st to 10th	Night	38% 7% 11% 24% 17% 3	2160
	11th to 20th	Night	38% 6% 10% 24% 19% 3	2160
	21st to end	Night	34% 5% 10% 23% 22% 5%	2376
November	1st to 10th	Night	36% 5% 9% 21% 23% 6%	2221
	11th to 20th	Night	34% 5% 11% 24% 22% 5%	2435
	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	38% 22% 26% 13% 2	246
	21st to end	Day	41% 22% 22% 11% 4	264
February	1st to 10th	Day	35% 23% 30% 9% 3	240
	11th to 20th	Day	43% 21% 27% 8%	240
	21st to end	Day	38% 21% 26% 13% 2	271
March	1st to 10th	Day	29% 23% 23% 19% 6%	420
	11th to 20th	Day	32% 21% 22% 20% 3 1	420
	21st to end	Day	28% 21% 24% 20% 7% 1	462
April	1st to 10th	Day	26% 23% 22% 20% 8% 1	420
	11th to 20th	Day	22% 17% 27% 20% 11% 3	412
	21st to end	Day	29% 16% 25% 17% 8% 4	420
May	1st to 10th	Day	25% 17% 27% 18% 9% 3	423
	11th to 20th	Day	24% 12% 25% 21% 13% 5%	447
	21st to end	Day	17% 9% 23% 24% 18% 9%	485
June	1st to 10th	Day	16% 8% 29% 23% 16% 8%	450
	11th to 20th	Day	15% 8% 27% 23% 19% 8%	450
	21st to end	Day	12% 9% 30% 26% 17% 6%	450
July	1st to 10th	Day	12% 4 20% 27% 23% 13%	445
	11th to 20th	Day	6% 4 20% 34% 25% 11%	444
	21st to end	Day	13% 5% 23% 27% 22% 10%	488
August	1st to 10th	Day	17% 6% 23% 20% 21% 13%	446
	11th to 20th	Day	15% 4 19% 26% 23% 12%	439
	21st to end	Day	14% 3 16% 27% 24% 16%	495
September	1st to 10th	Day	17% 4 19% 24% 24% 13%	450
	11th to 20th	Day	17% 5% 17% 28% 24% 8%	450
	21st to end	Day	29% 8% 19% 25% 15% 4	450
October	1st to 10th	Day	22% 9% 19% 28% 19% 3	450
	11th to 20th	Day	21% 13% 22% 28% 14% 2	450
	21st to end	Day	24% 15% 26% 23% 10% 2	495
November	1st to 10th	Day	20% 12% 27% 27% 12% 3	455
	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	26% 16% 22% 32% 3	732
	21st to end	Night	22% 20% 31% 25% 2	792
February	1st to 10th	Night	22% 19% 25% 31% 3	720
	11th to 20th	Night	28% 22% 27% 22% 1	703
	21st to end	Night	24% 18% 32% 24% 2	592
March	1st to 10th	Night	20% 16% 30% 28% 5%	720
	11th to 20th	Night	27% 16% 26% 23% 8% 1	720
	21st to end	Night	21% 14% 27% 30% 7% 1	792
April	1st to 10th	Night	21% 17% 25% 31% 7%	720
	11th to 20th	Night	20% 13% 24% 29% 13% 1	711
	21st to end	Night	19% 11% 22% 35% 11% 1	612
May	1st to 10th	Night	19% 7% 22% 35% 14% 2	540
	11th to 20th	Night	21% 8% 17% 35% 17% 1	531
	21st to end	Night	16% 2 11% 35% 30% 5%	584
June	1st to 10th	Night	12% 2 11% 43% 29% 2	496
	11th to 20th	Night	11% 3 11% 39% 34% 2	396
	21st to end	Night	10% 3 12% 44% 27% 4	540
July	1st to 10th	Night	13% 2 9% 36% 35% 6%	525
	11th to 20th	Night	7% 1 7% 32% 48% 4	522
	21st to end	Night	8% 3 9% 37% 38% 4	591
August	1st to 10th	Night	15% 3 8% 34% 35% 4	537
	11th to 20th	Night	15% 2 6% 34% 38% 5%	534
	21st to end	Night	12% 2 8% 34% 38% 7%	750
September	1st to 10th	Night	14% 4 9% 31% 35% 7%	720
	11th to 20th	Night	18% 5% 10% 29% 34% 5%	720
	21st to end	Night	23% 5% 14% 31% 25% 2	720
October	1st to 10th	Night	18% 7% 16% 29% 26% 3	720
	11th to 20th	Night	20% 11% 20% 31% 17% 1	720
	21st to end	Night	19% 10% 21% 35% 13% 2	792
November	1st to 10th	Night	17% 9% 22% 35% 15% 2	740
	11th to 20th	Night	21% 13% 20% 34% 11% 1	760
	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

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