Moody Gardens
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Moody Gardens clear sky chart from 2005-11-06 to 2025-04-11.

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	13% 7% 2 6% 4 4 5% 4 6% 8% 41%	113893
	Night	13% 7% 2 6% 4 4 4 3 5% 8% 43%	114572
Transparency	Day	38% 7% 15% 20% 14% 6%	117567
	Night	37% 6% 13% 19% 16% 8%	119027
Seeing	Day	12% 3 12% 25% 32% 16%	15243
	Night	14% 4 15% 28% 30% 9%	25236

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	21% 12% 3 7% 3 3 3 3 4 5% 37%	4077
	11th to 20th	Day	17% 8% 2 7% 4 3 3 3 4 6% 43%	4080
	21st to end	Day	25% 10% 3 7% 3 3 3 4 5% 5% 32%	4488
February	1st to 10th	Day	20% 10% 3 7% 4 4 3 3 4 5% 36%	1864
	11th to 20th	Day	23% 11% 3 6% 3 3 3 2 3 5% 38%	2032
	21st to end	Day	21% 11% 3 6% 4 3 3 3 4 6% 36%	1815
March	1st to 10th	Day	18% 8% 3 8% 4 5% 4 3 6% 7% 34%	4936
	11th to 20th	Day	15% 7% 2 7% 5% 4 4 3 5% 6% 43%	4980
	21st to end	Day	18% 9% 3 7% 4 3 4 2 4 6% 41%	5462
April	1st to 10th	Day	15% 8% 3 6% 5% 4 4 4 5% 6% 41%	2200
	11th to 20th	Day	14% 8% 3 7% 5% 4 5% 3 4 7% 40%	2240
	21st to end	Day	10% 7% 2 5% 4 4 4 4 6% 6% 47%	2280
May	1st to 10th	Day	17% 8% 3 8% 5% 6% 5% 4 6% 7% 29%	3765
	11th to 20th	Day	14% 6% 2 6% 4 4 4 4 5% 8% 42%	3986
	21st to end	Day	8% 6% 2 6% 6% 5% 7% 7% 10% 12% 31%	4477
June	1st to 10th	Day	5% 4 2 5% 4 4 5% 5% 8% 11% 46%	2470
	11th to 20th	Day	5% 3 1 5% 4 6% 6% 6% 9% 12% 43%	2470
	21st to end	Day	7% 4 2 5% 5% 5% 7% 6% 11% 12% 36%	2470
July	1st to 10th	Day	8% 6% 2 6% 5% 5% 7% 4 9% 13% 36%	4120
	11th to 20th	Day	5% 7% 3 10% 7% 7% 7% 7% 9% 10% 28%	4120
	21st to end	Day	10% 7% 3 8% 5% 6% 6% 5% 8% 11% 30%	4465
August	1st to 10th	Day	2 1 1 2 2 3 4 3 6% 11% 64%	4104
	11th to 20th	Day	3 2 1 3 3 4 5% 5% 10% 15% 51%	3772
	21st to end	Day	7% 4 2 6% 5% 6% 7% 6% 8% 11% 38%	4180
September	1st to 10th	Day	9% 6% 2 7% 5% 5% 7% 6% 8% 9% 37%	2108
	11th to 20th	Day	14% 6% 3 6% 5% 5% 5% 5% 7% 8% 37%	2090
	21st to end	Day	9% 6% 2 6% 3 4 4 4 6% 8% 49%	2090
October	1st to 10th	Day	6% 3 2 4 4 4 4 4 6% 8% 55%	1943
	11th to 20th	Day	10% 5% 1 4 3 4 4 3 4 6% 56%	1900
	21st to end	Day	12% 3 2 5% 3 3 3 3 4 7% 56%	2090
November	1st to 10th	Day	11% 5% 2 5% 4 4 3 4 5% 7% 49%	1958
	11th to 20th	Day	13% 6% 2 4 4 5% 4 4 5% 6% 48%	2000
	21st to end	Day	15% 7% 3 7% 4 3 4 3 5% 5% 44%	2000
December	1st to 10th	Day	23% 10% 3 7% 4 3 4 3 4 6% 36%	2982
	11th to 20th	Day	11% 8% 3 6% 5% 5% 4 3 5% 6% 44%	3391
	21st to end	Day	14% 7% 2 7% 4 4 4 3 5% 6% 45%	4488
January	1st to 10th	Night	20% 9% 3 6% 4 4 4 3 5% 5% 38%	5888
	11th to 20th	Night	16% 10% 3 6% 4 3 3 2 4 5% 44%	5900
	21st to end	Night	26% 10% 4 7% 4 3 3 3 4 6% 29%	6490
February	1st to 10th	Night	20% 10% 3 6% 4 3 3 3 4 6% 38%	2553
	11th to 20th	Night	20% 9% 3 6% 3 3 2 3 3 6% 41%	2253
	21st to end	Night	19% 10% 3 7% 4 3 4 3 4 5% 39%	1815
March	1st to 10th	Night	20% 11% 3 6% 3 3 3 3 5% 6% 37%	4919
	11th to 20th	Night	15% 9% 2 6% 4 3 4 3 4 5% 43%	4980
	21st to end	Night	15% 10% 3 5% 4 4 3 3 4 6% 42%	5467
April	1st to 10th	Night	14% 7% 2 6% 5% 4 4 3 5% 7% 42%	2200
	11th to 20th	Night	14% 6% 2 6% 4 3 4 3 6% 7% 44%	1893
	21st to end	Night	11% 6% 2 6% 5% 5% 3 4 6% 7% 44%	1900
May	1st to 10th	Night	22% 9% 3 6% 5% 4 4 4 5% 7% 31%	3130
	11th to 20th	Night	12% 6% 2 7% 4 4 5% 4 5% 7% 44%	2899
	21st to end	Night	11% 6% 2 6% 5% 5% 5% 5% 8% 11% 36%	3090
June	1st to 10th	Night	4 4 1 4 3 3 4 4 6% 11% 56%	1710
	11th to 20th	Night	4 4 1 4 5% 4 4 5% 7% 11% 51%	1710
	21st to end	Night	5% 4 2 6% 5% 5% 5% 5% 9% 12% 41%	1710
July	1st to 10th	Night	5% 6% 2 6% 5% 4 4 4 6% 13% 45%	2850
	11th to 20th	Night	2 3 2 7% 7% 6% 7% 5% 9% 14% 38%	2850
	21st to end	Night	7% 6% 3 8% 6% 5% 6% 5% 7% 12% 36%	3098
August	1st to 10th	Night	1 1 2 2 2 3 3 6% 9% 70%	2836
	11th to 20th	Night	2 2 1 3 2 3 4 4 7% 14% 57%	3057
	21st to end	Night	4 3 1 5% 4 6% 5% 5% 8% 13% 46%	3476
September	1st to 10th	Night	6% 5% 3 6% 5% 5% 5% 5% 7% 11% 42%	2066
	11th to 20th	Night	12% 6% 2 7% 4 4 5% 5% 7% 8% 40%	2090
	21st to end	Night	8% 5% 2 5% 3 4 4 3 4 9% 53%	2090
October	1st to 10th	Night	5% 4 2 5% 3 3 4 3 6% 7% 58%	2216
	11th to 20th	Night	9% 4 1 3 3 2 4 3 4 7% 60%	2280
	21st to end	Night	10% 5% 1 5% 3 3 3 2 4 5% 59%	2508
November	1st to 10th	Night	10% 5% 2 5% 4 3 4 4 5% 6% 52%	2340
	11th to 20th	Night	13% 5% 2 4 4 4 3 4 4 5% 51%	2400
	21st to end	Night	13% 7% 2 7% 4 4 4 3 5% 6% 44%	2400
December	1st to 10th	Night	23% 11% 3 8% 5% 4 3 2 4 6% 31%	4202
	11th to 20th	Night	12% 7% 3 7% 5% 4 4 4 5% 6% 43%	4816
	21st to end	Night	14% 7% 3 6% 4 4 3 3 4 5% 46%	6490

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	51% 4 6% 18% 16% 6%	4078
	11th to 20th	Day	41% 6% 9% 17% 19% 8%	4080
	21st to end	Day	53% 4 5% 13% 14% 10%	4488
February	1st to 10th	Day	50% 4 7% 15% 14% 10%	1864
	11th to 20th	Day	50% 4 9% 14% 16% 7%	2042
	21st to end	Day	50% 5% 10% 14% 14% 8%	1815
March	1st to 10th	Day	49% 6% 11% 15% 10% 10%	4936
	11th to 20th	Day	42% 5% 12% 11% 16% 13%	4980
	21st to end	Day	43% 5% 12% 18% 18% 3	5464
April	1st to 10th	Day	43% 6% 11% 17% 15% 8%	2200
	11th to 20th	Day	42% 5% 14% 17% 14% 8%	2240
	21st to end	Day	34% 6% 14% 21% 19% 5%	2280
May	1st to 10th	Day	47% 9% 17% 15% 9% 4	3800
	11th to 20th	Day	38% 7% 13% 21% 17% 4	3990
	21st to end	Day	35% 13% 17% 28% 7%	4489
June	1st to 10th	Day	26% 9% 21% 30% 14%	2470
	11th to 20th	Day	27% 9% 22% 29% 13% 1	2470
	21st to end	Day	34% 11% 23% 26% 6%	2470
July	1st to 10th	Day	36% 9% 32% 20% 2	4056
	11th to 20th	Day	44% 13% 23% 16% 3	4051
	21st to end	Day	43% 11% 24% 19% 2	4325
August	1st to 10th	Day	13% 6% 22% 45% 14%	4090
	11th to 20th	Day	19% 9% 42% 27% 3	3808
	21st to end	Day	36% 12% 18% 23% 9% 1	4179
September	1st to 10th	Day	37% 13% 18% 18% 11% 3	2108
	11th to 20th	Day	41% 8% 14% 21% 14% 2	2090
	21st to end	Day	32% 7% 15% 22% 15% 9%	2090
October	1st to 10th	Day	20% 4 8% 17% 18% 32%	3229
	11th to 20th	Day	21% 4 6% 24% 35% 10%	3140
	21st to end	Day	23% 4 7% 19% 37% 10%	3428
November	1st to 10th	Day	34% 6% 11% 23% 20% 7%	1958
	11th to 20th	Day	35% 5% 12% 17% 19% 12%	2000
	21st to end	Day	41% 5% 10% 18% 17% 8%	2000
December	1st to 10th	Day	51% 4 10% 20% 13% 3	2982
	11th to 20th	Day	39% 6% 11% 18% 17% 9%	3389
	21st to end	Day	39% 6% 8% 17% 20% 11%	4488
January	1st to 10th	Night	47% 5% 8% 16% 15% 9%	5888
	11th to 20th	Night	43% 4 6% 15% 23% 9%	5900
	21st to end	Night	56% 4 5% 11% 14% 10%	6490
February	1st to 10th	Night	47% 4 9% 11% 18% 12%	2553
	11th to 20th	Night	45% 3 9% 15% 17% 10%	2253
	21st to end	Night	47% 4 10% 13% 17% 9%	1815
March	1st to 10th	Night	47% 4 10% 16% 13% 10%	4919
	11th to 20th	Night	43% 5% 9% 13% 15% 15%	4980
	21st to end	Night	41% 5% 11% 16% 21% 7%	5467
April	1st to 10th	Night	40% 6% 11% 19% 15% 9%	2200
	11th to 20th	Night	37% 6% 13% 18% 14% 12%	1893
	21st to end	Night	36% 6% 13% 21% 18% 6%	1900
May	1st to 10th	Night	48% 8% 15% 16% 9% 5%	3160
	11th to 20th	Night	37% 6% 12% 22% 16% 7%	2900
	21st to end	Night	34% 9% 20% 27% 9% 1	3099
June	1st to 10th	Night	23% 5% 20% 35% 18%	1710
	11th to 20th	Night	24% 5% 20% 32% 16% 2	1710
	21st to end	Night	32% 9% 24% 26% 9%	1710
July	1st to 10th	Night	31% 7% 37% 23% 3	2805
	11th to 20th	Night	33% 11% 31% 21% 4	2796
	21st to end	Night	40% 12% 25% 21% 2	2999
August	1st to 10th	Night	11% 5% 19% 50% 15%	2826
	11th to 20th	Night	17% 7% 39% 33% 4	3087
	21st to end	Night	28% 13% 24% 25% 10% 1	3476
September	1st to 10th	Night	35% 9% 23% 19% 11% 3	2066
	11th to 20th	Night	41% 9% 13% 19% 15% 3	2090
	21st to end	Night	31% 6% 14% 24% 18% 8%	2090
October	1st to 10th	Night	20% 4 9% 18% 17% 32%	3697
	11th to 20th	Night	17% 5% 7% 24% 34% 14%	3779
	21st to end	Night	19% 3 7% 16% 39% 15%	4120
November	1st to 10th	Night	32% 5% 12% 23% 19% 8%	2340
	11th to 20th	Night	34% 4 11% 21% 20% 11%	2400
	21st to end	Night	40% 5% 9% 20% 18% 8%	2400
December	1st to 10th	Night	55% 4 8% 17% 11% 4	4202
	11th to 20th	Night	39% 5% 10% 17% 17% 12%	4817
	21st to end	Night	40% 4 8% 15% 26% 7%	6490

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	23% 8% 29% 30% 10%	300
	11th to 20th	Day	17% 9% 24% 36% 13% 1	300
	21st to end	Day	21% 9% 25% 35% 10%	330
February	1st to 10th	Day	28% 4 25% 30% 12% 2	300
	11th to 20th	Day	29% 7% 21% 33% 10% 1	300
	21st to end	Day	22% 9% 25% 36% 7%	249
March	1st to 10th	Day	15% 6% 29% 41% 9%	300
	11th to 20th	Day	19% 7% 23% 43% 7% 2	300
	21st to end	Day	15% 6% 25% 41% 13%	330
April	1st to 10th	Day	17% 7% 29% 33% 13%	300
	11th to 20th	Day	16% 7% 29% 27% 18% 1	438
	21st to end	Day	13% 5% 22% 38% 20% 2	460
May	1st to 10th	Day	13% 6% 20% 37% 22% 1	463
	11th to 20th	Day	10% 4 13% 37% 33% 3	618
	21st to end	Day	7% 1 11% 39% 38% 4	734
June	1st to 10th	Day	6% 1 4 28% 49% 13%	680
	11th to 20th	Day	8% 1 4 25% 49% 14%	680
	21st to end	Day	9% 1 5% 16% 44% 26%	680
July	1st to 10th	Day	7% 2 4 10% 43% 35%	671
	11th to 20th	Day	6% 1 6% 47% 39%	668
	21st to end	Day	6% 2 10% 50% 32%	739
August	1st to 10th	Day	2 1 6% 44% 47%	676
	11th to 20th	Day	4 1 5% 41% 49%	510
	21st to end	Day	11% 1 4 10% 34% 40%	539
September	1st to 10th	Day	14% 1 4 9% 36% 35%	318
	11th to 20th	Day	10% 2 2 12% 43% 32%	300
	21st to end	Day	11% 4 11% 46% 27%	300
October	1st to 10th	Day	8% 1 5% 26% 45% 15%	300
	11th to 20th	Day	10% 2 7% 25% 41% 16%	300
	21st to end	Day	13% 5% 17% 23% 36% 5%	330
November	1st to 10th	Day	14% 1 12% 33% 33% 7%	300
	11th to 20th	Day	14% 5% 14% 34% 27% 6%	300
	21st to end	Day	17% 6% 26% 31% 17% 3	300
December	1st to 10th	Day	21% 6% 15% 33% 19% 6%	300
	11th to 20th	Day	22% 5% 24% 29% 19%	300
	21st to end	Day	19% 3 22% 34% 21% 2	330
January	1st to 10th	Night	21% 7% 24% 32% 15% 1	1000
	11th to 20th	Night	20% 6% 26% 35% 13% 1	1000
	21st to end	Night	22% 7% 25% 34% 12%	1100
February	1st to 10th	Night	24% 5% 24% 33% 13% 1	953
	11th to 20th	Night	24% 7% 22% 32% 13%	699
	21st to end	Night	24% 8% 24% 35% 9%	495
March	1st to 10th	Night	20% 5% 26% 33% 15% 1	600
	11th to 20th	Night	16% 8% 23% 36% 17% 1	600
	21st to end	Night	14% 5% 21% 39% 18% 2	660
April	1st to 10th	Night	15% 6% 24% 38% 17%	600
	11th to 20th	Night	15% 8% 21% 35% 20%	565
	21st to end	Night	11% 5% 22% 40% 20% 1	570
May	1st to 10th	Night	13% 5% 20% 41% 21%	570
	11th to 20th	Night	10% 2 14% 43% 27% 4	561
	21st to end	Night	6% 2 11% 37% 40% 5%	617
June	1st to 10th	Night	4 1 4 28% 55% 8%	570
	11th to 20th	Night	5% 1 4 23% 56% 12%	570
	21st to end	Night	5% 1 3 19% 50% 22%	570
July	1st to 10th	Night	7% 1 3 12% 48% 30%	555
	11th to 20th	Night	2 1 8% 46% 43%	552
	21st to end	Night	4 4 6% 56% 30%	624
August	1st to 10th	Night	2 1 6% 52% 39%	567
	11th to 20th	Night	4 1 1 5% 49% 40%	564
	21st to end	Night	8% 1 2 11% 48% 30%	627
September	1st to 10th	Night	9% 1 4 13% 45% 29%	570
	11th to 20th	Night	15% 1 5% 14% 45% 20%	570
	21st to end	Night	10% 1 7% 15% 50% 17%	570
October	1st to 10th	Night	6% 1 6% 25% 50% 13%	696
	11th to 20th	Night	9% 3 11% 29% 40% 9%	760
	21st to end	Night	11% 4 15% 29% 34% 7%	836
November	1st to 10th	Night	11% 2 12% 31% 37% 6%	780
	11th to 20th	Night	15% 4 16% 33% 30% 2	800
	21st to end	Night	14% 5% 22% 37% 19% 3	800
December	1st to 10th	Night	22% 6% 16% 31% 22% 3	965
	11th to 20th	Night	19% 6% 20% 36% 18% 1	1000
	21st to end	Night	21% 6% 22% 34% 16% 1	1100

Page generated at 2025-04-08 08:17:27. Version ac07

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