Medoc Mountain State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Medoc Mountain State Park clear sky chart from 2005-11-06 to 2025-08-05.

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	13% 6% 2 6% 4 4 5% 4 6% 8% 42%	124974
	Night	14% 6% 2 6% 4 4 4 4 5% 7% 44%	123074
Transparency	Day	40% 4 12% 22% 17% 5%	128577
	Night	40% 4 10% 20% 20% 6%	127540
Seeing	Day	17% 11% 26% 24% 16% 5%	16248
	Night	17% 9% 27% 30% 15% 2	26125

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	15% 5% 2 5% 3 3 2 2 3 4 57%	4056
	11th to 20th	Day	12% 7% 2 5% 2 3 2 3 4 4 56%	4060
	21st to end	Day	14% 7% 2 7% 4 3 3 3 4 5% 47%	4466
February	1st to 10th	Day	14% 7% 2 6% 4 4 5% 3 6% 8% 43%	1800
	11th to 20th	Day	22% 6% 2 5% 3 4 3 3 4 5% 44%	1823
	21st to end	Day	17% 7% 2 6% 5% 3 4 3 5% 6% 41%	1710
March	1st to 10th	Day	20% 8% 2 6% 4 4 4 3 4 6% 39%	4935
	11th to 20th	Day	11% 6% 2 5% 3 3 3 3 4 6% 54%	4980
	21st to end	Day	15% 5% 2 5% 4 4 4 3 5% 6% 47%	5465
April	1st to 10th	Day	12% 5% 2 4 4 4 3 3 5% 7% 52%	2384
	11th to 20th	Day	11% 6% 2 4 5% 4 3 3 5% 8% 49%	2374
	21st to end	Day	14% 5% 2 6% 5% 4 5% 4 5% 7% 43%	2400
May	1st to 10th	Day	9% 6% 3 8% 5% 5% 6% 4 8% 11% 35%	5631
	11th to 20th	Day	19% 7% 3 7% 5% 5% 5% 5% 6% 9% 30%	5861
	21st to end	Day	13% 5% 2 6% 4 4 4 4 6% 8% 44%	6570
June	1st to 10th	Day	9% 5% 2 6% 5% 5% 6% 5% 7% 9% 41%	2800
	11th to 20th	Day	9% 4 2 5% 5% 5% 6% 5% 8% 11% 42%	2800
	21st to end	Day	6% 4 2 6% 5% 5% 6% 6% 8% 12% 39%	2758
July	1st to 10th	Day	8% 5% 2 7% 5% 6% 7% 6% 9% 11% 33%	5900
	11th to 20th	Day	9% 6% 2 9% 6% 6% 6% 6% 9% 12% 28%	5900
	21st to end	Day	7% 5% 2 7% 5% 6% 6% 5% 8% 12% 34%	6424
August	1st to 10th	Day	17% 9% 3 9% 6% 5% 6% 5% 7% 10% 23%	4156
	11th to 20th	Day	9% 6% 2 8% 5% 5% 7% 4 7% 11% 34%	3827
	21st to end	Day	6% 5% 2 6% 4 4 5% 5% 7% 11% 46%	4180
September	1st to 10th	Day	10% 5% 3 6% 5% 4 5% 4 6% 8% 44%	2280
	11th to 20th	Day	15% 6% 2 8% 5% 4 5% 3 5% 7% 41%	2252
	21st to end	Day	20% 7% 3 7% 4 4 4 3 5% 7% 36%	1995
October	1st to 10th	Day	15% 6% 2 5% 4 4 4 3 5% 6% 46%	1900
	11th to 20th	Day	14% 6% 2 4 3 3 3 2 3 6% 54%	1900
	21st to end	Day	12% 5% 2 6% 3 3 4 2 3 5% 55%	2090
November	1st to 10th	Day	13% 5% 1 5% 3 3 4 3 4 6% 53%	1957
	11th to 20th	Day	14% 6% 2 4 4 3 3 3 5% 5% 51%	1891
	21st to end	Day	15% 5% 2 4 3 3 3 3 4 5% 52%	1652
December	1st to 10th	Day	12% 6% 2 5% 4 4 3 3 4 6% 52%	2600
	11th to 20th	Day	16% 7% 3 7% 4 4 4 3 4 5% 45%	2990
	21st to end	Day	14% 6% 3 6% 3 3 4 3 5% 7% 45%	4207
January	1st to 10th	Night	12% 6% 2 5% 3 3 4 3 4 6% 53%	5889
	11th to 20th	Night	14% 6% 2 5% 3 2 3 3 3 5% 55%	5900
	21st to end	Night	16% 6% 2 6% 3 4 3 3 4 5% 48%	6490
February	1st to 10th	Night	18% 7% 1 5% 3 3 4 3 5% 7% 44%	2600
	11th to 20th	Night	20% 7% 2 5% 4 3 4 3 4 5% 41%	2461
	21st to end	Night	14% 7% 2 5% 3 4 3 3 5% 5% 48%	1916
March	1st to 10th	Night	19% 7% 2 6% 4 4 4 3 4 5% 42%	4918
	11th to 20th	Night	12% 6% 2 5% 3 3 3 3 5% 7% 51%	4980
	21st to end	Night	14% 5% 2 4 3 3 4 3 4 7% 51%	5467
April	1st to 10th	Night	14% 6% 2 6% 5% 4 3 3 5% 7% 47%	2015
	11th to 20th	Night	13% 5% 2 5% 4 4 3 3 5% 7% 50%	1975
	21st to end	Night	12% 5% 1 5% 4 5% 4 4 5% 7% 48%	2000
May	1st to 10th	Night	12% 8% 3 8% 5% 5% 5% 4 6% 8% 35%	4292
	11th to 20th	Night	21% 8% 3 7% 4 4 4 4 5% 7% 33%	4032
	21st to end	Night	15% 6% 2 6% 4 4 4 3 6% 8% 41%	4266
June	1st to 10th	Night	10% 5% 2 6% 5% 5% 5% 5% 9% 9% 39%	1600
	11th to 20th	Night	9% 6% 2 7% 5% 5% 5% 5% 7% 10% 40%	1600
	21st to end	Night	7% 5% 2 5% 5% 5% 6% 5% 8% 10% 41%	1633
July	1st to 10th	Night	10% 6% 3 7% 5% 5% 6% 6% 8% 12% 33%	4058
	11th to 20th	Night	12% 7% 3 9% 6% 6% 7% 5% 8% 11% 26%	4057
	21st to end	Night	11% 8% 3 7% 5% 5% 5% 5% 8% 10% 33%	4427
August	1st to 10th	Night	21% 8% 3 8% 6% 5% 5% 5% 7% 8% 24%	2861
	11th to 20th	Night	8% 7% 3 8% 5% 5% 6% 5% 7% 10% 37%	2967
	21st to end	Night	7% 5% 2 5% 5% 4 5% 4 8% 11% 44%	3476
September	1st to 10th	Night	11% 5% 2 7% 3 4 3 4 5% 9% 47%	1900
	11th to 20th	Night	14% 8% 2 7% 4 4 4 4 6% 6% 43%	1924
	21st to end	Night	21% 8% 3 6% 4 4 4 4 4 6% 36%	2183
October	1st to 10th	Night	15% 6% 2 6% 4 4 3 4 5% 6% 47%	2280
	11th to 20th	Night	12% 6% 2 5% 4 3 3 2 3 6% 54%	2280
	21st to end	Night	12% 4 2 4 3 3 3 3 5% 6% 54%	2508
November	1st to 10th	Night	13% 6% 2 5% 4 3 4 3 4 6% 50%	2341
	11th to 20th	Night	14% 5% 3 5% 4 4 3 3 5% 5% 49%	2505
	21st to end	Night	12% 5% 1 5% 4 4 3 3 4 6% 52%	2745
December	1st to 10th	Night	11% 5% 2 6% 4 3 3 3 4 5% 53%	4580
	11th to 20th	Night	17% 7% 3 8% 4 4 4 3 4 6% 39%	5205
	21st to end	Night	13% 6% 2 5% 3 4 3 3 5% 7% 48%	6743

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	35% 2 4 21% 30% 9%	4057
	11th to 20th	Day	33% 2 4 18% 33% 9%	4060
	21st to end	Day	40% 3 6% 24% 20% 7%	4466
February	1st to 10th	Day	39% 4 11% 24% 18% 4	1800
	11th to 20th	Day	44% 3 7% 19% 21% 6%	1832
	21st to end	Day	44% 4 11% 16% 21% 5%	1710
March	1st to 10th	Day	47% 3 6% 18% 16% 10%	4935
	11th to 20th	Day	34% 2 8% 20% 23% 13%	4980
	21st to end	Day	39% 3 11% 22% 19% 6%	5465
April	1st to 10th	Day	32% 4 11% 24% 22% 7%	2384
	11th to 20th	Day	34% 4 12% 24% 20% 6%	2374
	21st to end	Day	41% 4 12% 23% 16% 4	2400
May	1st to 10th	Day	43% 5% 19% 22% 10% 1	5663
	11th to 20th	Day	52% 5% 13% 20% 10% 1	5865
	21st to end	Day	38% 5% 13% 25% 17% 2	6585
June	1st to 10th	Day	38% 7% 14% 24% 16% 2	2800
	11th to 20th	Day	35% 7% 17% 25% 14% 2	2800
	21st to end	Day	34% 10% 17% 23% 15% 1	2758
July	1st to 10th	Day	42% 6% 19% 21% 10% 3	5835
	11th to 20th	Day	47% 8% 26% 14% 4 1	5831
	21st to end	Day	41% 7% 17% 24% 11%	6240
August	1st to 10th	Day	56% 6% 18% 16% 4	4143
	11th to 20th	Day	44% 5% 15% 25% 9% 1	3866
	21st to end	Day	33% 5% 15% 30% 15% 2	4180
September	1st to 10th	Day	37% 7% 15% 17% 19% 4	2280
	11th to 20th	Day	41% 6% 10% 22% 19% 2	2252
	21st to end	Day	48% 4 10% 20% 14% 4	1995
October	1st to 10th	Day	38% 3 6% 21% 26% 6%	3160
	11th to 20th	Day	23% 2 5% 20% 31% 20%	3140
	21st to end	Day	24% 2 6% 27% 27% 14%	3428
November	1st to 10th	Day	34% 3 8% 24% 26% 5%	1957
	11th to 20th	Day	36% 2 9% 22% 23% 7%	1891
	21st to end	Day	35% 3 7% 23% 27% 5%	1652
December	1st to 10th	Day	36% 3 7% 25% 23% 7%	2600
	11th to 20th	Day	43% 2 11% 20% 18% 5%	2986
	21st to end	Day	39% 3 12% 24% 20% 1	4207
January	1st to 10th	Night	34% 3 5% 18% 29% 12%	5889
	11th to 20th	Night	35% 3 5% 17% 34% 6%	5900
	21st to end	Night	40% 2 5% 20% 26% 6%	6490
February	1st to 10th	Night	42% 3 10% 21% 20% 5%	2600
	11th to 20th	Night	46% 3 8% 17% 20% 6%	2463
	21st to end	Night	39% 3 7% 22% 20% 8%	1916
March	1st to 10th	Night	47% 3 6% 14% 21% 10%	4918
	11th to 20th	Night	35% 2 8% 15% 23% 17%	4980
	21st to end	Night	36% 2 9% 24% 22% 6%	5467
April	1st to 10th	Night	38% 5% 9% 17% 24% 7%	2015
	11th to 20th	Night	35% 4 10% 23% 22% 6%	1975
	21st to end	Night	36% 4 11% 27% 18% 4	2000
May	1st to 10th	Night	46% 5% 17% 19% 12% 1	4322
	11th to 20th	Night	51% 5% 11% 18% 13% 1	4033
	21st to end	Night	41% 5% 13% 23% 16% 1	4273
June	1st to 10th	Night	37% 9% 15% 21% 17% 2	1600
	11th to 20th	Night	38% 8% 18% 18% 16% 2	1600
	21st to end	Night	36% 9% 14% 24% 16% 2	1633
July	1st to 10th	Night	43% 7% 20% 19% 10% 1	4015
	11th to 20th	Night	51% 10% 22% 13% 3 1	4006
	21st to end	Night	46% 6% 16% 20% 12%	4297
August	1st to 10th	Night	56% 5% 18% 15% 5% 1	2850
	11th to 20th	Night	41% 6% 20% 22% 9% 1	2994
	21st to end	Night	33% 5% 13% 29% 19% 1	3476
September	1st to 10th	Night	34% 8% 16% 20% 17% 5%	1900
	11th to 20th	Night	41% 6% 11% 20% 21% 2	1924
	21st to end	Night	49% 5% 11% 16% 15% 3	2183
October	1st to 10th	Night	41% 4 7% 20% 24% 4	3800
	11th to 20th	Night	25% 2 5% 18% 29% 20%	3779
	21st to end	Night	23% 2 6% 30% 23% 15%	4120
November	1st to 10th	Night	37% 3 8% 21% 26% 5%	2341
	11th to 20th	Night	37% 3 8% 17% 24% 10%	2505
	21st to end	Night	34% 3 7% 23% 27% 6%	2745
December	1st to 10th	Night	36% 2 6% 21% 29% 6%	4580
	11th to 20th	Night	48% 2 9% 17% 17% 7%	5208
	21st to end	Night	37% 3 11% 27% 20% 2	6743

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	26% 26% 33% 12% 3	300
	11th to 20th	Day	27% 29% 33% 10% 1	300
	21st to end	Day	20% 25% 41% 12% 1	330
February	1st to 10th	Day	21% 24% 38% 14% 3	300
	11th to 20th	Day	36% 24% 32% 8% 1	370
	21st to end	Day	26% 21% 32% 17% 4	414
March	1st to 10th	Day	23% 21% 34% 18% 4 1	500
	11th to 20th	Day	23% 19% 37% 15% 5% 1	500
	21st to end	Day	21% 17% 39% 17% 4 1	550
April	1st to 10th	Day	22% 18% 33% 20% 6% 1	500
	11th to 20th	Day	16% 17% 32% 23% 9% 3	492
	21st to end	Day	18% 12% 32% 27% 10% 1	500
May	1st to 10th	Day	14% 13% 39% 22% 10% 2	503
	11th to 20th	Day	18% 8% 28% 28% 14% 4	527
	21st to end	Day	20% 7% 21% 24% 21% 7%	573
June	1st to 10th	Day	11% 5% 26% 32% 21% 5%	530
	11th to 20th	Day	10% 4 22% 33% 23% 8%	530
	21st to end	Day	8% 4 18% 35% 27% 8%	530
July	1st to 10th	Day	11% 2 11% 33% 33% 10%	525
	11th to 20th	Day	8% 2 11% 32% 36% 12%	524
	21st to end	Day	10% 2 16% 35% 28% 9%	576
August	1st to 10th	Day	14% 4 19% 30% 24% 10%	502
	11th to 20th	Day	12% 3 17% 26% 30% 11%	479
	21st to end	Day	9% 2 14% 31% 27% 17%	539
September	1st to 10th	Day	13% 3 16% 28% 24% 16%	490
	11th to 20th	Day	16% 4 14% 30% 25% 11%	490
	21st to end	Day	25% 7% 22% 28% 15% 4	490
October	1st to 10th	Day	19% 7% 21% 23% 22% 8%	490
	11th to 20th	Day	13% 11% 27% 28% 17% 4	490
	21st to end	Day	14% 10% 29% 26% 16% 5%	539
November	1st to 10th	Day	18% 9% 32% 23% 15% 3	495
	11th to 20th	Day	18% 16% 30% 25% 10% 1	445
	21st to end	Day	25% 16% 24% 23% 10% 3	252
December	1st to 10th	Day	25% 16% 45% 8% 6% 1	200
	11th to 20th	Day	19% 19% 34% 23% 4 2	200
	21st to end	Day	25% 18% 31% 18% 8%	273
January	1st to 10th	Night	20% 19% 34% 22% 4	800
	11th to 20th	Night	22% 15% 34% 24% 5%	800
	21st to end	Night	19% 14% 40% 24% 3	880
February	1st to 10th	Night	23% 15% 37% 22% 4	800
	11th to 20th	Night	26% 19% 39% 15% 2	783
	21st to end	Night	19% 16% 37% 25% 3	660
March	1st to 10th	Night	18% 18% 34% 26% 4	800
	11th to 20th	Night	21% 14% 38% 20% 6% 1	800
	21st to end	Night	20% 12% 42% 21% 5%	880
April	1st to 10th	Night	19% 16% 35% 27% 4	800
	11th to 20th	Night	17% 11% 36% 28% 8%	791
	21st to end	Night	14% 8% 38% 33% 7%	800
May	1st to 10th	Night	14% 12% 34% 31% 9%	719
	11th to 20th	Night	20% 6% 26% 36% 12% 1	591
	21st to end	Night	15% 2 21% 36% 24% 1	585
June	1st to 10th	Night	10% 3 24% 40% 22% 1	400
	11th to 20th	Night	10% 3 16% 45% 23% 3	400
	21st to end	Night	8% 2 15% 47% 26% 2	433
July	1st to 10th	Night	10% 2 14% 40% 32% 3	585
	11th to 20th	Night	9% 1 9% 41% 34% 7%	582
	21st to end	Night	8% 2 14% 42% 30% 4	657
August	1st to 10th	Night	15% 2 11% 40% 29% 3	579
	11th to 20th	Night	13% 3 12% 37% 33% 4	668
	21st to end	Night	13% 2 12% 33% 36% 5%	836
September	1st to 10th	Night	13% 2 13% 33% 34% 5%	760
	11th to 20th	Night	18% 4 16% 29% 29% 4	760
	21st to end	Night	26% 3 20% 31% 19% 2	760
October	1st to 10th	Night	17% 4 18% 31% 24% 5%	760
	11th to 20th	Night	16% 8% 26% 30% 18% 2	760
	21st to end	Night	15% 8% 27% 29% 19% 2	836
November	1st to 10th	Night	17% 7% 30% 31% 14% 2	780
	11th to 20th	Night	16% 11% 31% 31% 11% 1	800
	21st to end	Night	15% 13% 29% 30% 13% 1	800
December	1st to 10th	Night	21% 13% 33% 25% 8%	800
	11th to 20th	Night	19% 11% 31% 33% 6%	800
	21st to end	Night	20% 13% 30% 32% 5%	880

Page generated at 2025-08-02 01:32:29. Version ac07

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