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 2026-08-15.

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	12% 6% 2 6% 4 4 5% 4 6% 9% 41%	143066
	Night	13% 7% 2 6% 4 4 4 3 5% 8% 44%	139122
Transparency	Day	37% 7% 17% 21% 13% 5%	146699
	Night	37% 6% 14% 20% 15% 7%	143556
Seeing	Day	12% 3 12% 24% 33% 17%	17166
	Night	14% 4 15% 28% 30% 10%	26910

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	18% 11% 3 7% 3 3 3 3 4 5% 41%	5289
	11th to 20th	Day	14% 7% 3 7% 4 4 3 3 4 6% 46%	5310
	21st to end	Day	24% 10% 4 9% 3 3 3 3 5% 5% 31%	5812
February	1st to 10th	Day	19% 10% 3 7% 4 4 3 3 4 5% 38%	1957
	11th to 20th	Day	22% 11% 3 6% 4 3 3 3 4 5% 37%	2136
	21st to end	Day	20% 11% 3 6% 4 3 3 3 4 6% 38%	1903
March	1st to 10th	Day	18% 9% 3 8% 4 5% 4 3 6% 7% 34%	5046
	11th to 20th	Day	15% 7% 2 7% 4 4 4 3 5% 6% 44%	5090
	21st to end	Day	17% 8% 3 7% 4 3 4 2 4 6% 42%	5583
April	1st to 10th	Day	15% 8% 3 6% 5% 4 4 4 5% 6% 40%	2310
	11th to 20th	Day	13% 8% 3 7% 5% 4 5% 3 5% 8% 39%	2478
	21st to end	Day	10% 7% 2 6% 5% 4 4 4 6% 7% 44%	2520
May	1st to 10th	Day	21% 9% 3 8% 5% 5% 5% 4 6% 7% 28%	7021
	11th to 20th	Day	11% 6% 2 7% 4 4 5% 4 7% 9% 40%	7449
	21st to end	Day	8% 6% 3 8% 6% 6% 7% 7% 10% 12% 27%	8392
June	1st to 10th	Day	5% 4 2 5% 5% 4 5% 6% 8% 11% 45%	2730
	11th to 20th	Day	6% 3 1 5% 5% 6% 6% 6% 9% 12% 42%	2730
	21st to end	Day	6% 4 2 5% 5% 5% 7% 5% 10% 12% 39%	2730
July	1st to 10th	Day	5% 4 2 5% 4 4 6% 4 8% 14% 44%	7680
	11th to 20th	Day	6% 6% 3 9% 6% 6% 7% 6% 9% 11% 31%	7680
	21st to end	Day	6% 5% 2 6% 4 5% 5% 5% 7% 11% 44%	8337
August	1st to 10th	Day	2 1 1 3 2 3 4 4 6% 11% 63%	4364
	11th to 20th	Day	3 2 1 3 3 4 5% 5% 10% 15% 51%	3944
	21st to end	Day	7% 5% 2 6% 5% 6% 6% 6% 8% 11% 38%	4312
September	1st to 10th	Day	9% 6% 2 7% 5% 5% 6% 6% 8% 9% 37%	2219
	11th to 20th	Day	13% 6% 3 6% 5% 5% 5% 5% 7% 8% 38%	2200
	21st to end	Day	8% 5% 2 5% 4 4 4 4 6% 8% 49%	2200
October	1st to 10th	Day	5% 3 2 4 4 4 4 4 6% 8% 56%	2045
	11th to 20th	Day	9% 4 1 4 3 4 4 3 4 6% 57%	2000
	21st to end	Day	12% 3 2 5% 3 3 3 3 4 7% 56%	2200
November	1st to 10th	Day	10% 5% 2 5% 4 4 3 4 5% 7% 50%	2058
	11th to 20th	Day	12% 6% 2 4 4 5% 4 4 5% 6% 48%	2100
	21st to end	Day	15% 7% 3 7% 4 3 4 3 5% 6% 44%	2100
December	1st to 10th	Day	23% 10% 2 7% 4 3 4 3 4 6% 36%	3073
	11th to 20th	Day	11% 8% 3 6% 5% 5% 4 3 4 6% 44%	3481
	21st to end	Day	13% 7% 2 7% 4 4 4 3 5% 6% 45%	4587
January	1st to 10th	Night	17% 8% 3 6% 4 4 4 3 5% 5% 43%	7634
	11th to 20th	Night	14% 9% 3 7% 4 3 3 3 4 5% 45%	7680
	21st to end	Night	25% 10% 4 9% 4 3 3 3 4 6% 30%	8402
February	1st to 10th	Night	19% 10% 3 6% 4 3 3 3 4 6% 39%	2680
	11th to 20th	Night	19% 9% 3 6% 3 3 3 3 3 6% 41%	2369
	21st to end	Night	18% 9% 3 7% 4 3 4 3 4 5% 40%	1903
March	1st to 10th	Night	20% 11% 3 6% 3 3 3 3 5% 6% 37%	5029
	11th to 20th	Night	15% 9% 2 6% 4 3 4 3 4 5% 44%	5090
	21st to end	Night	15% 10% 3 5% 4 4 3 3 4 6% 43%	5588
April	1st to 10th	Night	14% 7% 2 6% 5% 4 5% 3 5% 7% 41%	2310
	11th to 20th	Night	14% 6% 2 6% 4 3 4 3 5% 7% 46%	2088
	21st to end	Night	11% 6% 2 6% 5% 6% 4 4 7% 8% 43%	2100
May	1st to 10th	Night	23% 10% 3 7% 5% 4 4 4 5% 7% 27%	5832
	11th to 20th	Night	13% 6% 2 6% 4 5% 5% 4 5% 9% 42%	5417
	21st to end	Night	10% 8% 3 7% 5% 5% 5% 5% 8% 11% 33%	5793
June	1st to 10th	Night	4 4 1 5% 3 4 4 3 7% 11% 54%	1890
	11th to 20th	Night	5% 4 1 4 5% 4 4 4 7% 11% 50%	1890
	21st to end	Night	5% 4 2 6% 5% 5% 5% 5% 9% 12% 43%	1890
July	1st to 10th	Night	3 4 2 5% 4 3 4 4 6% 14% 52%	5308
	11th to 20th	Night	4 5% 2 7% 6% 6% 6% 5% 8% 12% 39%	5307
	21st to end	Night	4 4 2 6% 4 4 5% 4 7% 13% 46%	5770
August	1st to 10th	Night	1 1 2 2 2 3 3 6% 9% 70%	3016
	11th to 20th	Night	2 2 1 3 2 3 4 4 7% 14% 58%	3193
	21st to end	Night	4 3 1 5% 4 6% 5% 5% 8% 13% 46%	3586
September	1st to 10th	Night	6% 5% 3 6% 5% 6% 5% 5% 7% 10% 42%	2175
	11th to 20th	Night	11% 6% 2 7% 4 4 5% 5% 7% 8% 42%	2200
	21st to end	Night	8% 5% 2 5% 3 4 4 3 5% 9% 52%	2200
October	1st to 10th	Night	5% 4 2 5% 3 3 4 3 6% 7% 59%	2333
	11th to 20th	Night	8% 4 2 3 3 2 4 3 4 6% 61%	2400
	21st to end	Night	10% 5% 1 5% 3 3 3 2 4 5% 59%	2640
November	1st to 10th	Night	10% 5% 2 5% 4 3 4 3 5% 6% 54%	2460
	11th to 20th	Night	12% 5% 2 4 4 4 3 4 4 5% 53%	2520
	21st to end	Night	13% 7% 2 7% 4 4 4 3 5% 7% 44%	2520
December	1st to 10th	Night	24% 10% 3 8% 5% 4 3 2 4 6% 31%	4330
	11th to 20th	Night	12% 7% 3 7% 5% 4 4 4 5% 6% 43%	4946
	21st to end	Night	14% 7% 3 6% 4 4 3 3 4 6% 46%	6633

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	46% 4 9% 20% 15% 6%	5290
	11th to 20th	Day	39% 5% 8% 19% 18% 10%	5310
	21st to end	Day	55% 4 6% 12% 15% 8%	5812
February	1st to 10th	Day	49% 4 8% 15% 15% 10%	1957
	11th to 20th	Day	49% 4 9% 14% 15% 7%	2146
	21st to end	Day	48% 5% 10% 15% 15% 8%	1903
March	1st to 10th	Day	49% 6% 11% 15% 10% 10%	5046
	11th to 20th	Day	42% 5% 12% 12% 17% 13%	5090
	21st to end	Day	42% 6% 12% 19% 18% 3	5585
April	1st to 10th	Day	44% 6% 11% 17% 14% 8%	2310
	11th to 20th	Day	42% 5% 15% 17% 13% 8%	2478
	21st to end	Day	36% 7% 15% 20% 17% 5%	2520
May	1st to 10th	Day	51% 8% 15% 15% 10% 2	7056
	11th to 20th	Day	37% 8% 16% 22% 14% 3	7453
	21st to end	Day	40% 13% 19% 22% 5%	8405
June	1st to 10th	Day	27% 9% 21% 30% 13%	2730
	11th to 20th	Day	27% 10% 22% 28% 12% 1	2730
	21st to end	Day	32% 11% 23% 28% 6%	2730
July	1st to 10th	Day	28% 8% 42% 21% 1	7616
	11th to 20th	Day	42% 11% 29% 15% 3	7611
	21st to end	Day	31% 9% 24% 31% 5%	8155
August	1st to 10th	Day	14% 6% 23% 43% 13%	4350
	11th to 20th	Day	18% 9% 42% 28% 3	3980
	21st to end	Day	36% 12% 19% 23% 9% 1	4311
September	1st to 10th	Day	36% 13% 18% 18% 11% 3	2219
	11th to 20th	Day	40% 8% 14% 23% 14% 2	2200
	21st to end	Day	32% 7% 15% 23% 14% 9%	2200
October	1st to 10th	Day	20% 4 8% 17% 19% 31%	3331
	11th to 20th	Day	20% 4 6% 24% 35% 10%	3240
	21st to end	Day	23% 4 7% 19% 36% 10%	3538
November	1st to 10th	Day	33% 6% 11% 23% 21% 7%	2058
	11th to 20th	Day	35% 5% 12% 17% 19% 11%	2100
	21st to end	Day	41% 5% 10% 19% 17% 8%	2100
December	1st to 10th	Day	51% 3 10% 19% 13% 3	3073
	11th to 20th	Day	39% 6% 11% 18% 17% 9%	3479
	21st to end	Day	39% 6% 8% 17% 19% 11%	4587
January	1st to 10th	Night	43% 5% 11% 17% 16% 9%	7635
	11th to 20th	Night	41% 4 6% 16% 23% 11%	7680
	21st to end	Night	57% 4 6% 12% 14% 8%	8402
February	1st to 10th	Night	46% 4 9% 11% 18% 12%	2680
	11th to 20th	Night	45% 3 9% 15% 17% 10%	2369
	21st to end	Night	46% 4 10% 13% 18% 9%	1903
March	1st to 10th	Night	47% 4 10% 16% 13% 10%	5029
	11th to 20th	Night	42% 5% 9% 13% 16% 15%	5090
	21st to end	Night	40% 5% 10% 16% 21% 7%	5588
April	1st to 10th	Night	41% 6% 11% 19% 15% 9%	2310
	11th to 20th	Night	36% 6% 13% 20% 14% 11%	2088
	21st to end	Night	36% 6% 15% 20% 16% 6%	2100
May	1st to 10th	Night	53% 7% 12% 16% 9% 3	5862
	11th to 20th	Night	37% 6% 13% 26% 14% 4	5418
	21st to end	Night	40% 9% 22% 23% 6%	5805
June	1st to 10th	Night	24% 6% 20% 35% 16%	1890
	11th to 20th	Night	25% 5% 21% 32% 15% 2	1890
	21st to end	Night	31% 9% 24% 27% 9%	1890
July	1st to 10th	Night	24% 6% 43% 26% 2	5265
	11th to 20th	Night	36% 9% 34% 17% 4	5256
	21st to end	Night	29% 8% 22% 36% 5%	5641
August	1st to 10th	Night	11% 5% 20% 49% 14%	3006
	11th to 20th	Night	17% 7% 38% 34% 3	3223
	21st to end	Night	28% 13% 24% 25% 9% 1	3586
September	1st to 10th	Night	35% 9% 22% 19% 11% 3	2175
	11th to 20th	Night	39% 9% 14% 20% 16% 3	2200
	21st to end	Night	30% 6% 15% 24% 18% 7%	2200
October	1st to 10th	Night	20% 4 9% 18% 19% 31%	3814
	11th to 20th	Night	17% 5% 7% 25% 33% 14%	3899
	21st to end	Night	19% 3 7% 16% 39% 15%	4252
November	1st to 10th	Night	31% 5% 12% 23% 21% 8%	2460
	11th to 20th	Night	33% 3 11% 22% 20% 11%	2520
	21st to end	Night	40% 5% 10% 20% 18% 7%	2520
December	1st to 10th	Night	56% 4 8% 17% 11% 4	4330
	11th to 20th	Night	39% 5% 9% 17% 17% 12%	4947
	21st to end	Night	39% 4 8% 15% 26% 7%	6633

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% 27% 29% 12%	330
	11th to 20th	Day	16% 8% 24% 37% 14% 1	330
	21st to end	Day	22% 9% 24% 35% 9%	363
February	1st to 10th	Day	26% 4 23% 34% 12% 2	330
	11th to 20th	Day	27% 6% 21% 34% 12% 1	330
	21st to end	Day	22% 8% 24% 36% 10%	273
March	1st to 10th	Day	18% 6% 26% 40% 11%	330
	11th to 20th	Day	18% 7% 22% 42% 9% 2	330
	21st to end	Day	13% 6% 23% 38% 18% 2	363
April	1st to 10th	Day	17% 7% 28% 34% 15%	330
	11th to 20th	Day	17% 6% 27% 29% 20% 1	516
	21st to end	Day	14% 4 20% 41% 20% 1	540
May	1st to 10th	Day	16% 5% 20% 37% 20% 1	543
	11th to 20th	Day	11% 3 14% 38% 31% 3	712
	21st to end	Day	8% 1 10% 38% 38% 4	844
June	1st to 10th	Day	6% 1 3 27% 50% 13%	780
	11th to 20th	Day	8% 1 4 23% 49% 15%	780
	21st to end	Day	8% 1 4 15% 46% 26%	780
July	1st to 10th	Day	7% 2 3 9% 42% 37%	771
	11th to 20th	Day	6% 1 6% 46% 40%	768
	21st to end	Day	6% 2 9% 49% 34%	849
August	1st to 10th	Day	2 1 6% 41% 49%	776
	11th to 20th	Day	4 1 4 40% 50%	570
	21st to end	Day	11% 1 4 10% 33% 42%	583
September	1st to 10th	Day	14% 1 4 9% 40% 32%	349
	11th to 20th	Day	9% 2 2 12% 44% 32%	330
	21st to end	Day	11% 4 11% 47% 28%	330
October	1st to 10th	Day	7% 1 4 24% 47% 16%	330
	11th to 20th	Day	9% 2 6% 24% 42% 17%	330
	21st to end	Day	12% 5% 17% 23% 38% 5%	363
November	1st to 10th	Day	13% 1 12% 32% 34% 8%	330
	11th to 20th	Day	14% 5% 13% 32% 29% 7%	330
	21st to end	Day	17% 6% 25% 33% 17% 3	330
December	1st to 10th	Day	23% 6% 14% 34% 18% 6%	330
	11th to 20th	Day	22% 5% 23% 28% 22% 1	330
	21st to end	Day	19% 3 21% 32% 23% 3	363
January	1st to 10th	Night	20% 7% 24% 33% 15% 1	1050
	11th to 20th	Night	19% 6% 26% 35% 13% 1	1050
	21st to end	Night	22% 7% 25% 34% 12%	1155
February	1st to 10th	Night	23% 5% 25% 34% 13% 1	1000
	11th to 20th	Night	24% 7% 22% 33% 14% 1	735
	21st to end	Night	23% 7% 24% 36% 9%	519
March	1st to 10th	Night	21% 4 25% 33% 16% 1	630
	11th to 20th	Night	16% 7% 23% 35% 18% 1	630
	21st to end	Night	13% 5% 20% 38% 21% 3	693
April	1st to 10th	Night	16% 5% 23% 39% 16%	630
	11th to 20th	Night	14% 8% 21% 36% 19% 1	623
	21st to end	Night	12% 5% 21% 40% 21% 1	630
May	1st to 10th	Night	16% 4 20% 40% 20%	630
	11th to 20th	Night	10% 2 15% 44% 26% 3	621
	21st to end	Night	7% 1 10% 37% 41% 5%	683
June	1st to 10th	Night	5% 1 3 28% 55% 8%	630
	11th to 20th	Night	6% 1 3 24% 55% 11%	630
	21st to end	Night	5% 1 3 18% 50% 23%	630
July	1st to 10th	Night	7% 1 3 11% 49% 30%	615
	11th to 20th	Night	3 8% 45% 43%	612
	21st to end	Night	4 3 6% 57% 29%	690
August	1st to 10th	Night	1 1 5% 52% 40%	627
	11th to 20th	Night	4 1 5% 49% 41%	606
	21st to end	Night	8% 1 2 10% 47% 32%	660
September	1st to 10th	Night	9% 1 4 13% 46% 28%	600
	11th to 20th	Night	14% 1 5% 14% 47% 20%	600
	21st to end	Night	10% 1 7% 16% 50% 17%	600
October	1st to 10th	Night	5% 1 6% 24% 50% 14%	733
	11th to 20th	Night	8% 3 10% 29% 41% 9%	800
	21st to end	Night	10% 4 16% 29% 34% 7%	880
November	1st to 10th	Night	11% 2 12% 30% 38% 7%	820
	11th to 20th	Night	14% 4 16% 32% 32% 2	840
	21st to end	Night	14% 4 22% 38% 19% 3	840
December	1st to 10th	Night	23% 6% 15% 32% 21% 3	1013
	11th to 20th	Night	19% 6% 20% 36% 18% 2	1050
	21st to end	Night	21% 6% 21% 33% 18% 2	1155

Page generated at 2026-08-12 02:37:20. Version ac07

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