Beatrice High School
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Beatrice High School clear sky chart from 2005-11-06 to 2026-07-31.

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	10% 7% 3 7% 4 4 4 3 5% 7% 46%	137604
	Night	9% 6% 2 6% 4 4 4 3 5% 7% 50%	135731
Transparency	Day	36% 5% 12% 26% 18% 3	141267
	Night	33% 5% 12% 26% 20% 3	140135
Seeing	Day	14% 9% 31% 29% 14% 3	18154
	Night	13% 9% 34% 33% 10% 1	27968

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	10% 11% 4 11% 6% 4 5% 3 4 6% 36%	5289
	11th to 20th	Day	5% 8% 3 9% 6% 7% 6% 4 5% 5% 41%	5310
	21st to end	Day	5% 13% 5% 10% 4 4 3 3 5% 5% 41%	5812
February	1st to 10th	Day	9% 12% 4 7% 5% 5% 3 4 6% 8% 37%	1890
	11th to 20th	Day	7% 10% 3 8% 4 4 4 4 5% 8% 41%	1940
	21st to end	Day	7% 7% 3 6% 5% 4 4 3 5% 7% 49%	1730
March	1st to 10th	Day	12% 8% 3 5% 3 3 2 3 3 4 54%	4946
	11th to 20th	Day	10% 6% 2 4 3 3 4 3 5% 6% 53%	5090
	21st to end	Day	14% 10% 3 8% 5% 5% 3 3 5% 7% 37%	5583
April	1st to 10th	Day	14% 8% 3 5% 4 3 3 3 4 6% 47%	2331
	11th to 20th	Day	12% 8% 3 6% 4 4 4 4 4 7% 44%	2639
	21st to end	Day	20% 8% 2 7% 3 3 4 3 4 7% 38%	2730
May	1st to 10th	Day	11% 8% 3 5% 4 3 4 3 5% 6% 47%	7617
	11th to 20th	Day	11% 6% 2 5% 3 4 4 3 5% 6% 50%	7627
	21st to end	Day	17% 7% 3 6% 4 4 4 4 5% 6% 39%	8392
June	1st to 10th	Day	7% 4 2 5% 4 4 4 4 6% 9% 50%	2730
	11th to 20th	Day	9% 5% 1 5% 4 4 5% 3 7% 10% 48%	2730
	21st to end	Day	7% 5% 2 6% 4 4 5% 4 6% 8% 48%	2730
July	1st to 10th	Day	8% 5% 2 5% 4 4 5% 4 6% 8% 49%	6030
	11th to 20th	Day	7% 4 2 7% 4 5% 5% 4 6% 9% 46%	6030
	21st to end	Day	7% 5% 2 6% 4 4 5% 3 6% 8% 51%	6553
August	1st to 10th	Day	6% 4 2 6% 5% 5% 5% 4 6% 10% 47%	4234
	11th to 20th	Day	12% 6% 2 6% 4 3 4 4 6% 8% 45%	4171
	21st to end	Day	5% 4 2 6% 4 4 4 4 6% 9% 53%	4619
September	1st to 10th	Day	13% 4 2 4 3 3 3 2 5% 7% 54%	2261
	11th to 20th	Day	9% 5% 2 4 4 3 3 2 6% 7% 53%	2200
	21st to end	Day	10% 5% 2 4 3 3 3 2 4 6% 58%	2200
October	1st to 10th	Day	14% 5% 2 5% 3 3 4 3 4 5% 54%	2080
	11th to 20th	Day	10% 5% 2 5% 3 3 3 2 4 5% 58%	2000
	21st to end	Day	13% 8% 2 6% 4 3 3 3 3 5% 51%	2200
November	1st to 10th	Day	9% 5% 2 5% 3 3 3 3 4 6% 57%	1868
	11th to 20th	Day	8% 7% 3 5% 3 3 4 3 5% 7% 53%	1890
	21st to end	Day	14% 8% 2 6% 3 3 3 3 5% 7% 46%	1769
December	1st to 10th	Day	5% 5% 2 5% 4 4 5% 3 6% 7% 54%	2690
	11th to 20th	Day	7% 9% 3 8% 5% 4 4 3 4 6% 47%	3106
	21st to end	Day	16% 10% 4 13% 4 4 4 3 4 5% 33%	4587
January	1st to 10th	Night	9% 9% 4 13% 5% 4 5% 3 5% 6% 37%	7634
	11th to 20th	Night	5% 6% 2 7% 4 5% 6% 4 6% 6% 49%	7680
	21st to end	Night	9% 11% 5% 9% 4 4 4 3 4 5% 44%	8402
February	1st to 10th	Night	9% 11% 3 7% 4 4 6% 4 6% 5% 41%	2730
	11th to 20th	Night	8% 9% 3 8% 5% 4 5% 4 6% 8% 42%	2585
	21st to end	Night	9% 7% 2 6% 4 4 4 3 4 6% 53%	2076
March	1st to 10th	Night	11% 6% 2 5% 3 3 4 3 4 5% 54%	5130
	11th to 20th	Night	8% 6% 1 4 3 3 4 3 5% 6% 58%	5090
	21st to end	Night	13% 8% 3 6% 4 4 4 4 6% 8% 40%	5588
April	1st to 10th	Night	12% 6% 2 5% 4 4 3 4 4 8% 48%	2289
	11th to 20th	Night	10% 7% 2 6% 4 3 4 3 6% 7% 47%	1928
	21st to end	Night	15% 6% 2 5% 5% 3 3 3 6% 8% 44%	1890
May	1st to 10th	Night	12% 6% 2 5% 3 3 3 3 5% 6% 52%	5266
	11th to 20th	Night	12% 5% 2 4 3 3 3 3 4 7% 56%	5265
	21st to end	Night	16% 7% 2 6% 4 3 4 3 5% 6% 44%	5793
June	1st to 10th	Night	6% 4 2 4 4 4 3 4 7% 9% 53%	1890
	11th to 20th	Night	6% 4 1 4 3 4 4 4 6% 10% 54%	1869
	21st to end	Night	5% 3 2 4 4 3 3 3 5% 9% 59%	1890
July	1st to 10th	Night	7% 5% 2 5% 3 3 4 4 6% 9% 52%	4168
	11th to 20th	Night	5% 3 2 5% 4 4 5% 3 6% 8% 53%	4167
	21st to end	Night	4 4 1 5% 4 4 4 3 6% 9% 56%	4539
August	1st to 10th	Night	2 3 1 4 4 4 5% 4 6% 10% 56%	2926
	11th to 20th	Night	11% 5% 1 5% 3 4 4 3 5% 9% 49%	2888
	21st to end	Night	6% 4 1 4 3 4 3 3 5% 8% 58%	3288
September	1st to 10th	Night	8% 4 1 3 3 3 3 3 4 7% 61%	2135
	11th to 20th	Night	8% 4 1 3 3 3 4 4 6% 7% 58%	2200
	21st to end	Night	8% 4 1 4 3 3 3 3 4 5% 61%	2200
October	1st to 10th	Night	12% 6% 2 4 3 3 3 3 5% 6% 53%	2299
	11th to 20th	Night	11% 6% 2 4 3 2 3 2 4 4 58%	2400
	21st to end	Night	13% 7% 2 4 3 2 3 3 4 5% 54%	2640
November	1st to 10th	Night	7% 3 2 5% 3 4 3 3 4 7% 59%	2648
	11th to 20th	Night	8% 6% 2 5% 3 3 4 4 5% 6% 55%	2730
	21st to end	Night	11% 7% 3 5% 3 3 2 3 4 6% 52%	2845
December	1st to 10th	Night	5% 5% 2 4 4 4 4 3 5% 6% 60%	4720
	11th to 20th	Night	9% 7% 3 7% 4 3 3 3 5% 7% 49%	5310
	21st to end	Night	15% 13% 5% 9% 4 3 4 3 4 5% 36%	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	50% 4 10% 23% 12% 1	5290
	11th to 20th	Day	43% 4 13% 19% 18% 2	5310
	21st to end	Day	46% 4 12% 23% 16% 1	5812
February	1st to 10th	Day	44% 5% 17% 22% 9% 3	1890
	11th to 20th	Day	41% 6% 12% 24% 14% 3	1949
	21st to end	Day	35% 5% 11% 26% 19% 3	1730
March	1st to 10th	Day	35% 3 8% 25% 21% 8%	4946
	11th to 20th	Day	32% 4 8% 24% 25% 6%	5090
	21st to end	Day	45% 7% 20% 20% 6% 2	5585
April	1st to 10th	Day	39% 5% 13% 24% 16% 3	2331
	11th to 20th	Day	40% 6% 12% 24% 17% 3	2639
	21st to end	Day	46% 5% 10% 25% 13% 1	2730
May	1st to 10th	Day	36% 5% 9% 27% 20% 2	7655
	11th to 20th	Day	34% 5% 10% 23% 23% 4	7631
	21st to end	Day	44% 6% 10% 26% 14% 1	8405
June	1st to 10th	Day	29% 8% 15% 33% 13% 2	2730
	11th to 20th	Day	31% 6% 14% 29% 19% 2	2730
	21st to end	Day	32% 8% 13% 28% 15% 5%	2730
July	1st to 10th	Day	32% 6% 13% 30% 18% 1	5966
	11th to 20th	Day	33% 7% 13% 27% 17% 2	5961
	21st to end	Day	30% 6% 13% 29% 19% 3	6371
August	1st to 10th	Day	31% 7% 16% 26% 16% 4	4220
	11th to 20th	Day	36% 6% 17% 23% 17% 1	4210
	21st to end	Day	27% 5% 16% 27% 17% 7%	4618
September	1st to 10th	Day	31% 4 13% 27% 20% 5%	2261
	11th to 20th	Day	30% 5% 12% 29% 23% 2	2200
	21st to end	Day	28% 4 8% 32% 24% 3	2200
October	1st to 10th	Day	21% 4 6% 18% 47% 3	3392
	11th to 20th	Day	20% 3 10% 28% 30% 9%	3240
	21st to end	Day	32% 3 11% 27% 24% 3	3538
November	1st to 10th	Day	29% 4 13% 29% 22% 3	1868
	11th to 20th	Day	32% 4 11% 28% 23% 2	1890
	21st to end	Day	39% 4 11% 28% 16% 2	1769
December	1st to 10th	Day	29% 4 14% 33% 19% 1	2690
	11th to 20th	Day	38% 4 16% 31% 11% 1	3103
	21st to end	Day	55% 4 9% 23% 8% 1	4587
January	1st to 10th	Night	49% 4 12% 20% 13% 2	7635
	11th to 20th	Night	33% 4 11% 29% 20% 3	7680
	21st to end	Night	44% 3 12% 19% 18% 4	8402
February	1st to 10th	Night	43% 6% 12% 21% 15% 3	2730
	11th to 20th	Night	40% 5% 13% 25% 15% 3	2586
	21st to end	Night	34% 4 10% 24% 21% 7%	2076
March	1st to 10th	Night	32% 4 8% 26% 26% 4	5130
	11th to 20th	Night	27% 4 7% 23% 31% 9%	5090
	21st to end	Night	40% 7% 20% 25% 7% 2	5588
April	1st to 10th	Night	35% 6% 10% 28% 18% 4	2289
	11th to 20th	Night	36% 5% 10% 27% 18% 4	1928
	21st to end	Night	39% 5% 12% 26% 17% 1	1890
May	1st to 10th	Night	34% 5% 9% 27% 23% 3	5293
	11th to 20th	Night	30% 5% 9% 25% 25% 5%	5266
	21st to end	Night	40% 6% 12% 23% 18% 1	5805
June	1st to 10th	Night	26% 8% 15% 30% 19% 2	1890
	11th to 20th	Night	24% 6% 14% 31% 19% 5%	1869
	21st to end	Night	22% 5% 15% 33% 21% 4	1890
July	1st to 10th	Night	29% 6% 14% 27% 20% 4	4125
	11th to 20th	Night	28% 6% 14% 27% 23% 3	4116
	21st to end	Night	24% 6% 17% 28% 24% 2	4410
August	1st to 10th	Night	22% 6% 18% 27% 22% 5%	2916
	11th to 20th	Night	34% 5% 14% 29% 16% 2	2915
	21st to end	Night	24% 5% 16% 29% 17% 9%	3288
September	1st to 10th	Night	24% 4 13% 28% 23% 7%	2135
	11th to 20th	Night	25% 5% 11% 32% 23% 4	2200
	21st to end	Night	25% 5% 7% 28% 32% 3	2200
October	1st to 10th	Night	21% 4 8% 17% 44% 6%	3754
	11th to 20th	Night	21% 3 7% 32% 26% 10%	3899
	21st to end	Night	30% 3 8% 30% 26% 2	4252
November	1st to 10th	Night	25% 4 13% 27% 26% 5%	2648
	11th to 20th	Night	29% 5% 11% 30% 22% 3	2730
	21st to end	Night	34% 4 11% 27% 21% 3	2845
December	1st to 10th	Night	26% 4 14% 36% 18% 1	4720
	11th to 20th	Night	35% 4 14% 32% 15% 1	5312
	21st to end	Night	51% 4 10% 25% 9% 1	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	18% 15% 36% 23% 6% 2	330
	11th to 20th	Day	20% 16% 37% 21% 5%	330
	21st to end	Day	14% 12% 45% 22% 6%	363
February	1st to 10th	Day	13% 21% 47% 17% 2	330
	11th to 20th	Day	17% 13% 44% 18% 8%	330
	21st to end	Day	10% 19% 47% 20% 3	273
March	1st to 10th	Day	17% 14% 42% 22% 4 1	330
	11th to 20th	Day	27% 14% 31% 21% 6% 2	330
	21st to end	Day	29% 15% 40% 12% 3 1	363
April	1st to 10th	Day	25% 19% 36% 17% 3 1	351
	11th to 20th	Day	18% 17% 40% 19% 5%	677
	21st to end	Day	23% 18% 31% 19% 8% 1	750
May	1st to 10th	Day	17% 10% 36% 25% 10% 2	753
	11th to 20th	Day	18% 9% 33% 27% 11% 3	775
	21st to end	Day	20% 7% 31% 29% 11% 2	844
June	1st to 10th	Day	7% 5% 24% 37% 22% 6%	780
	11th to 20th	Day	8% 5% 34% 31% 18% 3	780
	21st to end	Day	10% 7% 36% 33% 13% 2	780
July	1st to 10th	Day	10% 3 19% 35% 26% 7%	771
	11th to 20th	Day	7% 2 17% 40% 24% 9%	768
	21st to end	Day	9% 2 16% 41% 28% 5%	845
August	1st to 10th	Day	7% 3 20% 42% 24% 3	726
	11th to 20th	Day	10% 4 17% 43% 22% 3	715
	21st to end	Day	10% 3 19% 38% 24% 6%	773
September	1st to 10th	Day	15% 3 22% 38% 18% 4	391
	11th to 20th	Day	9% 3 27% 35% 21% 5%	330
	21st to end	Day	15% 8% 30% 30% 15% 3	330
October	1st to 10th	Day	20% 8% 27% 26% 15% 5%	330
	11th to 20th	Day	8% 18% 44% 22% 7% 1	330
	21st to end	Day	19% 17% 35% 20% 7% 2	363
November	1st to 10th	Day	15% 15% 41% 20% 8% 1	330
	11th to 20th	Day	15% 14% 42% 22% 7% 1	330
	21st to end	Day	24% 12% 33% 22% 8%	330
December	1st to 10th	Day	9% 12% 44% 27% 6% 1	330
	11th to 20th	Day	16% 15% 38% 23% 8%	330
	21st to end	Day	19% 15% 41% 22% 3 1	363
January	1st to 10th	Night	12% 11% 37% 34% 6% 1	1050
	11th to 20th	Night	13% 12% 38% 29% 7%	1050
	21st to end	Night	15% 8% 44% 28% 5%	1155
February	1st to 10th	Night	15% 11% 41% 29% 4	1050
	11th to 20th	Night	13% 15% 40% 28% 4	951
	21st to end	Night	13% 15% 44% 24% 5%	692
March	1st to 10th	Night	14% 15% 39% 26% 6%	683
	11th to 20th	Night	19% 12% 36% 27% 5%	630
	21st to end	Night	20% 12% 42% 21% 5%	693
April	1st to 10th	Night	16% 13% 43% 22% 5%	630
	11th to 20th	Night	16% 14% 40% 26% 4 1	623
	21st to end	Night	18% 9% 37% 28% 6% 1	630
May	1st to 10th	Night	18% 7% 35% 31% 8%	630
	11th to 20th	Night	15% 8% 33% 33% 10% 1	621
	21st to end	Night	15% 7% 31% 34% 13% 1	683
June	1st to 10th	Night	8% 4 27% 41% 19% 1	630
	11th to 20th	Night	9% 4 33% 40% 14%	630
	21st to end	Night	6% 4 37% 42% 11%	630
July	1st to 10th	Night	8% 2 18% 44% 27%	615
	11th to 20th	Night	4 1 19% 49% 26% 1	612
	21st to end	Night	4 1 17% 50% 26% 1	687
August	1st to 10th	Night	3 2 21% 49% 23% 2	597
	11th to 20th	Night	6% 2 19% 49% 21% 2	594
	21st to end	Night	7% 2 21% 43% 24% 3	660
September	1st to 10th	Night	10% 3 27% 41% 17% 2	600
	11th to 20th	Night	11% 3 28% 42% 17% 1	600
	21st to end	Night	10% 5% 30% 40% 15% 1	600
October	1st to 10th	Night	15% 8% 31% 33% 13% 1	699
	11th to 20th	Night	16% 10% 38% 29% 8%	800
	21st to end	Night	17% 11% 32% 31% 8% 1	880
November	1st to 10th	Night	10% 11% 33% 36% 9%	1008
	11th to 20th	Night	12% 11% 42% 30% 6%	1050
	21st to end	Night	16% 10% 34% 29% 9% 1	1050
December	1st to 10th	Night	12% 11% 41% 31% 6%	1050
	11th to 20th	Night	15% 12% 35% 32% 6%	1050
	21st to end	Night	18% 12% 34% 30% 5%	1155

Page generated at 2026-07-28 02:25:21. Version ac07

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