Lost Maples State Natural Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lost Maples State Natural Area clear sky chart from 2005-11-06 to 2025-01-22.

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 5% 4 4 4 3 5% 7% 48%	105200
	Night	13% 6% 2 4 3 3 3 3 5% 7% 52%	104323
Transparency	Day	35% 4 9% 21% 19% 11%	109096
	Night	32% 4 10% 20% 20% 13%	108554
Seeing	Day	15% 9% 25% 30% 17% 3	15008
	Night	16% 8% 27% 35% 14% 1	25082

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	11% 6% 2 4 2 3 2 2 4 6% 58%	2937
	11th to 20th	Day	10% 9% 2 3 2 2 2 3 4 5% 58%	3044
	21st to end	Day	14% 7% 2 5% 3 3 3 3 5% 9% 47%	3497
February	1st to 10th	Day	13% 8% 2 5% 4 3 3 2 4 6% 50%	1900
	11th to 20th	Day	15% 8% 2 5% 3 4 3 4 4 6% 47%	1849
	21st to end	Day	14% 6% 2 4 2 3 3 3 4 6% 53%	1570
March	1st to 10th	Day	15% 8% 2 7% 4 3 2 2 4 5% 46%	3244
	11th to 20th	Day	19% 11% 3 9% 4 4 3 3 4 5% 36%	3480
	21st to end	Day	13% 6% 2 5% 3 4 4 3 5% 6% 48%	3814
April	1st to 10th	Day	14% 7% 2 5% 4 3 3 3 6% 7% 46%	2090
	11th to 20th	Day	17% 6% 2 5% 4 3 3 3 5% 7% 45%	2231
	21st to end	Day	14% 8% 3 5% 4 3 4 2 4 6% 47%	2304
May	1st to 10th	Day	20% 8% 3 6% 5% 4 4 3 6% 6% 37%	4082
	11th to 20th	Day	15% 7% 2 6% 4 4 4 3 5% 7% 44%	4082
	21st to end	Day	12% 7% 3 6% 4 5% 5% 4 6% 8% 40%	4477
June	1st to 10th	Day	7% 5% 1 6% 4 3 4 4 6% 9% 49%	2470
	11th to 20th	Day	9% 5% 2 5% 5% 5% 5% 4 6% 8% 47%	2470
	21st to end	Day	10% 6% 2 6% 6% 5% 5% 5% 7% 9% 39%	2470
July	1st to 10th	Day	8% 6% 2 5% 5% 4 5% 5% 6% 9% 47%	4120
	11th to 20th	Day	6% 4 2 5% 4 4 5% 4 6% 9% 51%	4120
	21st to end	Day	9% 5% 2 6% 5% 5% 5% 4 7% 10% 42%	4442
August	1st to 10th	Day	2 2 1 3 3 3 3 3 5% 7% 68%	3785
	11th to 20th	Day	4 3 1 3 3 4 3 3 6% 9% 60%	3726
	21st to end	Day	5% 4 2 6% 5% 5% 5% 4 6% 9% 48%	4158
September	1st to 10th	Day	12% 7% 3 7% 6% 5% 5% 3 6% 6% 40%	2090
	11th to 20th	Day	10% 6% 2 6% 5% 6% 5% 5% 6% 7% 42%	2090
	21st to end	Day	9% 6% 2 7% 4 4 5% 4 6% 7% 47%	2090
October	1st to 10th	Day	8% 5% 2 6% 4 3 4 3 5% 7% 53%	2090
	11th to 20th	Day	14% 5% 2 4 3 4 3 3 5% 6% 51%	2071
	21st to end	Day	13% 5% 2 5% 3 2 3 2 3 4 57%	2090
November	1st to 10th	Day	15% 7% 2 6% 4 3 4 3 4 6% 47%	1898
	11th to 20th	Day	11% 8% 2 5% 3 4 3 3 4 6% 52%	1800
	21st to end	Day	15% 8% 2 5% 3 3 3 3 4 5% 49%	1800
December	1st to 10th	Day	23% 9% 3 6% 3 3 3 2 3 5% 40%	2940
	11th to 20th	Day	15% 9% 3 5% 4 4 3 3 5% 5% 45%	3391
	21st to end	Day	12% 6% 2 4 2 2 2 2 3 4 61%	4488
January	1st to 10th	Night	12% 5% 2 5% 3 3 3 2 4 6% 56%	4238
	11th to 20th	Night	10% 5% 2 3 2 2 2 2 3 4 66%	4174
	21st to end	Night	19% 7% 2 5% 3 3 2 2 4 5% 47%	4192
February	1st to 10th	Night	14% 7% 2 4 3 2 2 2 5% 6% 52%	2280
	11th to 20th	Night	15% 8% 2 4 3 3 3 3 4 5% 51%	2218
	21st to end	Night	14% 5% 2 5% 3 3 3 3 5% 6% 49%	1884
March	1st to 10th	Night	13% 9% 2 5% 3 3 3 3 5% 6% 47%	3614
	11th to 20th	Night	16% 13% 3 7% 4 3 4 3 4 4 38%	3480
	21st to end	Night	14% 9% 3 5% 3 3 3 3 4 5% 49%	3817
April	1st to 10th	Night	10% 7% 2 5% 4 3 3 3 5% 6% 51%	2090
	11th to 20th	Night	16% 6% 3 6% 3 3 4 3 4 5% 47%	1894
	21st to end	Night	17% 7% 2 4 4 2 3 3 4 6% 48%	1875
May	1st to 10th	Night	22% 10% 2 5% 3 3 3 3 4 6% 40%	2823
	11th to 20th	Night	12% 6% 2 4 4 3 3 3 4 6% 52%	2823
	21st to end	Night	13% 7% 2 4 3 3 4 3 6% 8% 48%	3090
June	1st to 10th	Night	4 3 1 3 3 3 3 4 6% 10% 60%	1710
	11th to 20th	Night	6% 4 2 3 3 3 4 5% 5% 8% 57%	1710
	21st to end	Night	8% 5% 1 5% 4 4 3 3 6% 10% 52%	1710
July	1st to 10th	Night	6% 3 2 4 3 4 4 4 6% 10% 53%	2850
	11th to 20th	Night	5% 4 1 4 3 4 4 4 6% 9% 56%	2850
	21st to end	Night	12% 7% 2 5% 4 3 3 4 5% 9% 45%	3116
August	1st to 10th	Night	2 2 1 2 2 2 3 3 5% 7% 72%	3155
	11th to 20th	Night	3 2 1 3 2 3 3 4 6% 10% 62%	3113
	21st to end	Night	6% 5% 2 4 3 4 4 4 7% 10% 52%	3508
September	1st to 10th	Night	10% 6% 2 5% 3 5% 4 3 5% 9% 48%	2090
	11th to 20th	Night	11% 7% 2 5% 4 4 4 4 5% 7% 47%	2090
	21st to end	Night	8% 5% 2 5% 4 3 4 3 5% 8% 52%	2090
October	1st to 10th	Night	7% 4 2 4 4 3 3 3 4 8% 59%	2090
	11th to 20th	Night	13% 5% 1 4 3 2 3 2 4 6% 55%	2090
	21st to end	Night	15% 4 1 3 2 2 2 2 3 4 63%	2508
November	1st to 10th	Night	13% 7% 2 4 3 3 2 2 4 6% 55%	2395
	11th to 20th	Night	10% 7% 2 4 3 3 2 3 4 6% 57%	2600
	21st to end	Night	16% 7% 1 4 3 3 3 3 5% 6% 50%	2600
December	1st to 10th	Night	24% 7% 3 5% 3 3 4 3 4 5% 40%	4250
	11th to 20th	Night	20% 8% 2 4 3 3 3 2 3 4 50%	4816
	21st to end	Night	16% 6% 1 3 2 2 2 2 3 6% 58%	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	30% 2 3 16% 26% 23%	2938
	11th to 20th	Day	31% 1 5% 13% 29% 20%	3044
	21st to end	Day	37% 3 6% 15% 28% 11%	3497
February	1st to 10th	Day	38% 3 5% 13% 22% 19%	1900
	11th to 20th	Day	40% 4 5% 16% 20% 15%	1859
	21st to end	Day	34% 3 7% 16% 22% 18%	1570
March	1st to 10th	Day	43% 2 6% 12% 21% 16%	3244
	11th to 20th	Day	53% 3 6% 11% 16% 11%	3480
	21st to end	Day	36% 4 8% 16% 18% 18%	3814
April	1st to 10th	Day	39% 4 8% 16% 18% 15%	2090
	11th to 20th	Day	40% 4 7% 19% 17% 14%	2231
	21st to end	Day	41% 3 6% 19% 18% 12%	2304
May	1st to 10th	Day	49% 4 9% 14% 16% 8%	4120
	11th to 20th	Day	40% 4 8% 20% 20% 9%	4086
	21st to end	Day	41% 5% 11% 26% 13% 3	4489
June	1st to 10th	Day	30% 5% 15% 27% 20% 3	2470
	11th to 20th	Day	35% 6% 12% 25% 18% 5%	2470
	21st to end	Day	39% 7% 11% 23% 16% 4	2470
July	1st to 10th	Day	32% 6% 17% 36% 8% 1	4056
	11th to 20th	Day	28% 7% 15% 32% 16% 2	4051
	21st to end	Day	32% 8% 19% 29% 12% 1	4302
August	1st to 10th	Day	16% 4 11% 41% 26% 1	3772
	11th to 20th	Day	21% 5% 22% 39% 12% 2	3762
	21st to end	Day	30% 9% 16% 25% 19% 2	4157
September	1st to 10th	Day	43% 6% 10% 18% 16% 7%	2090
	11th to 20th	Day	39% 7% 11% 21% 17% 5%	2090
	21st to end	Day	35% 5% 10% 20% 18% 12%	2090
October	1st to 10th	Day	20% 3 6% 14% 25% 32%	3480
	11th to 20th	Day	30% 4 6% 16% 21% 23%	3427
	21st to end	Day	29% 3 5% 15% 35% 13%	3428
November	1st to 10th	Day	39% 4 8% 19% 18% 12%	1898
	11th to 20th	Day	36% 4 6% 17% 20% 18%	1800
	21st to end	Day	40% 2 5% 17% 21% 14%	1800
December	1st to 10th	Day	49% 3 6% 16% 16% 10%	2940
	11th to 20th	Day	41% 4 6% 14% 19% 15%	3389
	21st to end	Day	29% 2 3 17% 28% 20%	4488
January	1st to 10th	Night	30% 2 3 13% 28% 24%	4238
	11th to 20th	Night	25% 2 3 17% 27% 26%	4174
	21st to end	Night	42% 2 4 12% 26% 15%	4192
February	1st to 10th	Night	34% 3 7% 13% 22% 21%	2280
	11th to 20th	Night	36% 3 6% 17% 21% 17%	2218
	21st to end	Night	35% 3 7% 15% 21% 18%	1884
March	1st to 10th	Night	40% 4 7% 14% 21% 14%	3614
	11th to 20th	Night	50% 4 7% 12% 14% 13%	3480
	21st to end	Night	38% 4 8% 15% 16% 18%	3817
April	1st to 10th	Night	34% 4 10% 17% 17% 17%	2090
	11th to 20th	Night	40% 4 9% 14% 17% 17%	1894
	21st to end	Night	40% 3 9% 18% 17% 13%	1875
May	1st to 10th	Night	47% 3 9% 17% 13% 11%	2850
	11th to 20th	Night	34% 3 11% 23% 20% 9%	2824
	21st to end	Night	36% 5% 14% 27% 12% 7%	3099
June	1st to 10th	Night	19% 6% 19% 33% 20% 2	1710
	11th to 20th	Night	25% 5% 15% 28% 22% 6%	1710
	21st to end	Night	28% 5% 18% 28% 16% 4	1710
July	1st to 10th	Night	25% 8% 23% 37% 7% 1	2805
	11th to 20th	Night	24% 8% 19% 30% 18% 1	2796
	21st to end	Night	35% 7% 21% 29% 9% 1	3017
August	1st to 10th	Night	13% 5% 16% 43% 22%	3144
	11th to 20th	Night	17% 7% 28% 37% 10% 2	3143
	21st to end	Night	26% 10% 19% 27% 16% 2	3508
September	1st to 10th	Night	34% 7% 12% 22% 18% 7%	2090
	11th to 20th	Night	36% 7% 17% 20% 15% 6%	2090
	21st to end	Night	31% 6% 12% 21% 18% 12%	2090
October	1st to 10th	Night	17% 3 7% 16% 22% 34%	3480
	11th to 20th	Night	26% 3 8% 14% 29% 19%	3460
	21st to end	Night	27% 2 5% 18% 34% 15%	4120
November	1st to 10th	Night	33% 3 7% 20% 22% 14%	2395
	11th to 20th	Night	30% 3 7% 21% 20% 18%	2600
	21st to end	Night	36% 4 8% 16% 20% 17%	2600
December	1st to 10th	Night	46% 4 8% 15% 14% 13%	4250
	11th to 20th	Night	41% 3 5% 12% 21% 18%	4817
	21st to end	Night	31% 2 4 16% 28% 19%	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	25% 14% 37% 18% 6% 1	300
	11th to 20th	Day	23% 16% 35% 19% 6% 1	300
	21st to end	Day	20% 20% 33% 22% 5%	300
February	1st to 10th	Day	29% 14% 32% 18% 7%	270
	11th to 20th	Day	27% 17% 33% 17% 6%	270
	21st to end	Day	25% 22% 39% 14% 1	225
March	1st to 10th	Day	21% 23% 39% 14% 2	270
	11th to 20th	Day	23% 22% 38% 14% 3	270
	21st to end	Day	20% 21% 44% 12% 2 1	297
April	1st to 10th	Day	23% 20% 37% 19% 1	270
	11th to 20th	Day	19% 19% 40% 18% 3	429
	21st to end	Day	17% 16% 46% 18% 4	484
May	1st to 10th	Day	21% 11% 40% 23% 5%	653
	11th to 20th	Day	19% 11% 34% 28% 7% 1	675
	21st to end	Day	19% 10% 33% 28% 9%	734
June	1st to 10th	Day	7% 5% 23% 45% 19% 1	680
	11th to 20th	Day	11% 3 23% 45% 16% 1	680
	21st to end	Day	12% 3 16% 38% 26% 5%	680
July	1st to 10th	Day	11% 4 13% 38% 28% 6%	671
	11th to 20th	Day	6% 2 7% 42% 36% 5%	668
	21st to end	Day	6% 1 9% 42% 35% 7%	728
August	1st to 10th	Day	1 1 6% 47% 37% 8%	487
	11th to 20th	Day	8% 1 8% 39% 36% 8%	477
	21st to end	Day	5% 3 6% 36% 39% 10%	530
September	1st to 10th	Day	10% 2 11% 33% 36% 8%	300
	11th to 20th	Day	6% 1 8% 34% 45% 7%	300
	21st to end	Day	10% 2 11% 37% 34% 6%	300
October	1st to 10th	Day	8% 4 15% 42% 27% 4	300
	11th to 20th	Day	13% 4 22% 42% 17% 2	300
	21st to end	Day	19% 14% 26% 27% 11% 3	330
November	1st to 10th	Day	21% 8% 34% 25% 11% 1	300
	11th to 20th	Day	21% 10% 32% 22% 11% 4	300
	21st to end	Day	25% 16% 34% 15% 8% 1	300
December	1st to 10th	Day	20% 15% 29% 26% 9% 1	300
	11th to 20th	Day	21% 19% 31% 21% 7% 1	300
	21st to end	Day	17% 17% 32% 27% 7% 1	330
January	1st to 10th	Night	17% 12% 30% 33% 7% 1	1000
	11th to 20th	Night	21% 11% 30% 31% 7%	950
	21st to end	Night	22% 11% 29% 30% 8%	840
February	1st to 10th	Night	22% 13% 31% 28% 6%	760
	11th to 20th	Night	23% 13% 33% 27% 4	744
	21st to end	Night	21% 13% 41% 23% 2	628
March	1st to 10th	Night	24% 12% 35% 25% 4	692
	11th to 20th	Night	21% 11% 35% 29% 5%	570
	21st to end	Night	20% 11% 42% 22% 4	627
April	1st to 10th	Night	12% 16% 44% 25% 3	570
	11th to 20th	Night	19% 15% 43% 21% 2	563
	21st to end	Night	20% 11% 45% 20% 4	570
May	1st to 10th	Night	18% 11% 43% 24% 4	570
	11th to 20th	Night	17% 8% 36% 32% 6%	561
	21st to end	Night	17% 9% 36% 31% 7%	617
June	1st to 10th	Night	5% 2 30% 48% 15%	570
	11th to 20th	Night	9% 3 36% 44% 8%	570
	21st to end	Night	9% 4 26% 42% 19% 1	570
July	1st to 10th	Night	10% 3 15% 50% 21% 1	555
	11th to 20th	Night	5% 2 16% 50% 26% 2	552
	21st to end	Night	7% 2 11% 52% 27% 1	624
August	1st to 10th	Night	3 1 10% 53% 33% 1	567
	11th to 20th	Night	5% 1 7% 51% 35% 1	564
	21st to end	Night	8% 2 9% 42% 36% 3	627
September	1st to 10th	Night	11% 2 9% 44% 32% 2	570
	11th to 20th	Night	12% 1 11% 41% 32% 2	570
	21st to end	Night	9% 3 14% 38% 31% 4	570
October	1st to 10th	Night	9% 3 14% 45% 29% 1	570
	11th to 20th	Night	16% 5% 22% 36% 19% 2	570
	21st to end	Night	17% 8% 25% 29% 20% 2	836
November	1st to 10th	Night	18% 5% 22% 37% 17% 2	835
	11th to 20th	Night	14% 8% 25% 37% 14% 2	1000
	21st to end	Night	21% 10% 26% 31% 11% 1	1000
December	1st to 10th	Night	19% 8% 26% 36% 11% 1	1000
	11th to 20th	Night	24% 11% 26% 31% 8%	1000
	21st to end	Night	18% 11% 28% 34% 8%	1100

Page generated at 2025-01-19 02:06:50. Version ac07

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