North Platte
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the North Platte clear sky chart from 2005-11-06 to 2024-10-25.

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	8% 6% 2 5% 3 3 4 3 5% 7% 53%	101096
	Night	8% 6% 2 6% 4 4 4 4 5% 7% 51%	97911
Transparency	Day	29% 6% 14% 27% 19% 5%	100843
	Night	31% 6% 14% 27% 18% 4	97754
Seeing	Day	10% 8% 30% 33% 15% 3	15738
	Night	10% 8% 37% 37% 9%	25622

By Month

Percentage Cloud Cover SW (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	7% 11% 4 5% 3 3 3 3 4 5% 52%	2538
	11th to 20th	Day	5% 9% 3 7% 4 4 5% 4 7% 7% 45%	2540
	21st to end	Day	4 6% 4 8% 3 3 4 3 5% 7% 52%	2861
February	1st to 10th	Day	7% 9% 4 9% 6% 3 4 4 5% 7% 42%	1833
	11th to 20th	Day	5% 9% 3 7% 4 4 3 4 6% 6% 48%	1849
	21st to end	Day	7% 7% 3 5% 3 3 3 3 5% 6% 56%	1570
March	1st to 10th	Day	8% 4 2 4 3 3 4 3 6% 7% 57%	3130
	11th to 20th	Day	10% 6% 2 4 2 3 3 2 4 6% 59%	3386
	21st to end	Day	9% 9% 3 6% 4 3 4 4 6% 8% 46%	3925
April	1st to 10th	Day	11% 6% 2 4 3 3 4 3 5% 6% 53%	2280
	11th to 20th	Day	13% 7% 2 5% 4 4 4 3 5% 7% 44%	2270
	21st to end	Day	14% 6% 1 4 4 3 4 3 5% 7% 49%	2470
May	1st to 10th	Day	11% 5% 2 5% 4 3 5% 4 6% 7% 47%	4120
	11th to 20th	Day	11% 4 2 5% 3 4 4 3 5% 8% 50%	4082
	21st to end	Day	13% 5% 2 5% 3 3 4 4 6% 8% 48%	4667
June	1st to 10th	Day	6% 3 1 3 3 3 3 4 6% 9% 58%	2660
	11th to 20th	Day	7% 4 1 4 4 3 4 4 6% 7% 55%	2660
	21st to end	Day	3 3 2 3 4 3 4 4 6% 8% 60%	2660
July	1st to 10th	Day	7% 3 1 4 4 4 4 3 6% 8% 56%	4430
	11th to 20th	Day	4 3 2 4 3 4 5% 5% 7% 9% 55%	4430
	21st to end	Day	3 2 1 3 3 4 4 4 6% 9% 59%	4722
August	1st to 10th	Day	10% 5% 2 5% 3 3 4 4 7% 8% 48%	4103
	11th to 20th	Day	9% 6% 2 6% 3 4 5% 4 6% 7% 47%	3987
	21st to end	Day	4 3 1 4 3 3 3 3 5% 8% 63%	4180
September	1st to 10th	Day	8% 4 1 4 3 3 3 3 5% 6% 61%	2258
	11th to 20th	Day	6% 3 1 5% 3 3 4 3 5% 6% 60%	2090
	21st to end	Day	9% 4 1 3 3 3 3 3 3 6% 62%	2090
October	1st to 10th	Day	12% 5% 1 3 3 3 3 2 4 6% 59%	2090
	11th to 20th	Day	8% 5% 1 4 2 3 3 2 4 5% 60%	1902
	21st to end	Day	11% 6% 2 4 3 2 3 2 3 6% 57%	1823
November	1st to 10th	Day	4 5% 1 4 4 4 4 3 5% 7% 58%	1673
	11th to 20th	Day	5% 6% 2 4 3 3 3 3 4 6% 62%	1710
	21st to end	Day	7% 8% 2 4 3 2 3 3 5% 6% 57%	1710
December	1st to 10th	Day	5% 8% 3 6% 5% 4 3 3 4 7% 53%	1677
	11th to 20th	Day	6% 7% 2 5% 4 3 3 3 4 7% 55%	1926
	21st to end	Day	13% 13% 3 6% 4 4 3 3 4 5% 42%	2794
January	1st to 10th	Night	6% 9% 3 10% 5% 5% 4 4 5% 7% 43%	4417
	11th to 20th	Night	3 8% 3 7% 4 4 4 3 5% 7% 52%	4430
	21st to end	Night	3 7% 3 8% 5% 4 5% 4 5% 6% 50%	4803
February	1st to 10th	Night	8% 10% 4 8% 5% 4 4 3 6% 6% 43%	2361
	11th to 20th	Night	4 8% 2 8% 6% 5% 4 5% 6% 7% 46%	2218
	21st to end	Night	5% 6% 2 7% 4 3 4 3 5% 7% 52%	1884
March	1st to 10th	Night	9% 6% 1 5% 3 3 4 3 5% 5% 55%	3734
	11th to 20th	Night	8% 7% 2 5% 3 3 3 3 4 5% 56%	3576
	21st to end	Night	12% 8% 3 7% 4 3 4 4 6% 8% 42%	3708
April	1st to 10th	Night	12% 7% 2 4 3 3 4 4 6% 8% 47%	1900
	11th to 20th	Night	12% 6% 2 5% 4 5% 4 4 7% 6% 47%	1857
	21st to end	Night	13% 6% 2 5% 4 5% 3 5% 5% 7% 45%	1710
May	1st to 10th	Night	17% 5% 2 5% 3 4 5% 4 6% 7% 41%	2850
	11th to 20th	Night	10% 5% 3 5% 4 4 4 4 6% 8% 48%	2823
	21st to end	Night	13% 5% 2 6% 3 3 4 4 6% 7% 45%	2916
June	1st to 10th	Night	5% 4 2 4 4 4 4 4 6% 10% 52%	1520
	11th to 20th	Night	8% 4 2 5% 4 4 4 4 5% 10% 50%	1520
	21st to end	Night	4 3 2 5% 4 4 6% 4 8% 10% 50%	1520
July	1st to 10th	Night	9% 4 2 5% 4 4 4 4 6% 8% 51%	2540
	11th to 20th	Night	4 4 2 6% 5% 5% 4 5% 8% 9% 48%	2540
	21st to end	Night	3 2 1 4 4 4 5% 4 7% 8% 59%	2841
August	1st to 10th	Night	6% 5% 2 6% 5% 5% 4 4 8% 11% 43%	2836
	11th to 20th	Night	9% 5% 2 6% 5% 4 5% 4 6% 8% 45%	2848
	21st to end	Night	4 4 1 4 3 4 4 5% 7% 9% 55%	3487
September	1st to 10th	Night	7% 4 1 4 3 3 3 3 6% 7% 59%	1920
	11th to 20th	Night	6% 4 1 4 3 4 3 3 5% 6% 60%	2090
	21st to end	Night	8% 4 1 4 3 3 2 3 3 6% 63%	2090
October	1st to 10th	Night	12% 4 1 4 2 3 3 3 4 6% 58%	2090
	11th to 20th	Night	8% 4 1 3 3 3 3 3 3 6% 62%	2255
	21st to end	Night	9% 6% 2 4 2 2 3 3 5% 5% 59%	2639
November	1st to 10th	Night	4 4 1 5% 3 3 4 3 5% 7% 62%	2405
	11th to 20th	Night	6% 5% 2 5% 4 3 4 4 5% 7% 56%	2470
	21st to end	Night	6% 6% 2 5% 3 3 3 3 5% 7% 56%	2470
December	1st to 10th	Night	5% 7% 3 5% 4 3 3 3 5% 6% 56%	2499
	11th to 20th	Night	5% 6% 2 5% 3 3 4 3 5% 6% 58%	3271
	21st to end	Night	14% 12% 2 5% 3 3 3 3 4 6% 45%	4873

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% 4 11% 34% 15% 1	2539
	11th to 20th	Day	36% 9% 11% 26% 15% 3	2540
	21st to end	Day	31% 6% 17% 28% 16% 2	2861
February	1st to 10th	Day	41% 5% 15% 21% 13% 4	1833
	11th to 20th	Day	36% 5% 13% 25% 17% 4	1859
	21st to end	Day	29% 5% 14% 27% 19% 6%	1570
March	1st to 10th	Day	26% 5% 10% 25% 29% 5%	3130
	11th to 20th	Day	28% 4 13% 31% 22% 2	3386
	21st to end	Day	35% 7% 23% 28% 6% 1	3925
April	1st to 10th	Day	31% 5% 16% 27% 17% 4	2280
	11th to 20th	Day	39% 6% 13% 23% 16% 4	2273
	21st to end	Day	35% 5% 13% 29% 17% 2	2470
May	1st to 10th	Day	31% 8% 15% 21% 17% 8%	4120
	11th to 20th	Day	31% 8% 15% 28% 16% 2	4086
	21st to end	Day	32% 9% 16% 29% 12% 3	4667
June	1st to 10th	Day	22% 7% 20% 35% 14% 2	2660
	11th to 20th	Day	26% 7% 14% 27% 19% 7%	2660
	21st to end	Day	20% 8% 12% 30% 24% 5%	2660
July	1st to 10th	Day	26% 7% 11% 25% 26% 5%	4361
	11th to 20th	Day	23% 7% 14% 32% 20% 5%	4355
	21st to end	Day	18% 7% 15% 27% 23% 10%	4572
August	1st to 10th	Day	32% 8% 14% 25% 18% 2	4090
	11th to 20th	Day	35% 7% 14% 22% 20% 2	4026
	21st to end	Day	21% 5% 17% 24% 20% 13%	4179
September	1st to 10th	Day	24% 5% 10% 27% 24% 10%	2258
	11th to 20th	Day	24% 6% 11% 26% 27% 5%	2090
	21st to end	Day	25% 4 8% 30% 27% 7%	2090
October	1st to 10th	Day	29% 4 8% 26% 27% 6%	2090
	11th to 20th	Day	25% 4 10% 31% 21% 8%	1902
	21st to end	Day	30% 4 11% 28% 21% 6%	1823
November	1st to 10th	Day	25% 4 13% 30% 22% 6%	1673
	11th to 20th	Day	25% 3 11% 29% 27% 4	1710
	21st to end	Day	28% 4 12% 28% 23% 5%	1710
December	1st to 10th	Day	32% 5% 13% 30% 18% 3	1677
	11th to 20th	Day	29% 5% 13% 34% 18% 1	1924
	21st to end	Day	43% 6% 11% 26% 12% 2	2794
January	1st to 10th	Night	40% 6% 12% 25% 15% 1	4417
	11th to 20th	Night	31% 5% 18% 26% 19% 1	4430
	21st to end	Night	34% 7% 15% 28% 16% 1	4803
February	1st to 10th	Night	40% 6% 14% 23% 15% 4	2361
	11th to 20th	Night	36% 5% 15% 26% 15% 3	2218
	21st to end	Night	31% 5% 12% 24% 22% 7%	1884
March	1st to 10th	Night	29% 5% 10% 21% 28% 7%	3734
	11th to 20th	Night	29% 5% 11% 29% 22% 3	3576
	21st to end	Night	39% 9% 20% 24% 8% 1	3708
April	1st to 10th	Night	33% 7% 15% 24% 18% 4	1900
	11th to 20th	Night	35% 6% 14% 25% 16% 3	1857
	21st to end	Night	37% 7% 14% 26% 14% 2	1710
May	1st to 10th	Night	38% 8% 15% 22% 13% 4	2850
	11th to 20th	Night	32% 9% 17% 30% 10% 2	2824
	21st to end	Night	35% 10% 17% 27% 9% 2	2917
June	1st to 10th	Night	26% 8% 24% 28% 12% 2	1520
	11th to 20th	Night	30% 8% 16% 25% 14% 7%	1520
	21st to end	Night	26% 9% 17% 25% 21% 3	1520
July	1st to 10th	Night	31% 6% 14% 29% 19% 2	2500
	11th to 20th	Night	29% 7% 17% 25% 18% 3	2492
	21st to end	Night	21% 6% 16% 25% 23% 10%	2752
August	1st to 10th	Night	33% 8% 17% 27% 13% 2	2826
	11th to 20th	Night	36% 7% 15% 23% 16% 2	2875
	21st to end	Night	25% 7% 14% 26% 19% 10%	3487
September	1st to 10th	Night	23% 5% 10% 25% 26% 10%	1920
	11th to 20th	Night	24% 6% 12% 27% 24% 7%	2090
	21st to end	Night	24% 5% 9% 26% 29% 7%	2090
October	1st to 10th	Night	28% 5% 9% 24% 27% 5%	2090
	11th to 20th	Night	24% 4 9% 30% 25% 9%	2255
	21st to end	Night	28% 4 12% 25% 23% 8%	2639
November	1st to 10th	Night	22% 5% 12% 30% 23% 8%	2405
	11th to 20th	Night	27% 5% 12% 26% 24% 6%	2470
	21st to end	Night	28% 4 11% 29% 23% 5%	2470
December	1st to 10th	Night	29% 4 14% 29% 19% 4	2499
	11th to 20th	Night	27% 4 12% 38% 18% 1	3272
	21st to end	Night	40% 5% 11% 31% 12% 1	4873

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	10% 4 42% 31% 13% 1	270
	11th to 20th	Day	11% 12% 33% 38% 5% 1	270
	21st to end	Day	8% 9% 47% 24% 10% 3	297
February	1st to 10th	Day	7% 15% 47% 27% 3	270
	11th to 20th	Day	11% 9% 45% 26% 7% 2	270
	21st to end	Day	12% 11% 50% 21% 6%	225
March	1st to 10th	Day	9% 13% 36% 28% 12% 2	270
	11th to 20th	Day	15% 7% 33% 34% 8% 2	270
	21st to end	Day	17% 14% 39% 19% 8% 1	357
April	1st to 10th	Day	12% 19% 38% 23% 7%	460
	11th to 20th	Day	17% 20% 31% 27% 6%	471
	21st to end	Day	18% 12% 32% 25% 10% 1	650
May	1st to 10th	Day	13% 12% 34% 29% 11% 2	653
	11th to 20th	Day	17% 8% 31% 28% 12% 3	675
	21st to end	Day	15% 9% 31% 28% 16% 2	734
June	1st to 10th	Day	6% 5% 26% 32% 22% 8%	680
	11th to 20th	Day	6% 9% 35% 35% 13% 2	680
	21st to end	Day	4 5% 29% 40% 20% 2	680
July	1st to 10th	Day	6% 3 24% 40% 23% 4	671
	11th to 20th	Day	4 3 22% 43% 24% 4	668
	21st to end	Day	5% 2 17% 43% 27% 5%	739
August	1st to 10th	Day	9% 3 17% 42% 25% 4	676
	11th to 20th	Day	8% 4 21% 43% 22% 3	637
	21st to end	Day	5% 2 25% 41% 22% 5%	539
September	1st to 10th	Day	9% 4 22% 40% 21% 5%	468
	11th to 20th	Day	3 5% 20% 40% 26% 6%	300
	21st to end	Day	14% 8% 27% 29% 19% 3	300
October	1st to 10th	Day	15% 6% 21% 32% 21% 6%	300
	11th to 20th	Day	8% 10% 38% 32% 8% 4	300
	21st to end	Day	16% 14% 26% 29% 13% 3	311
November	1st to 10th	Day	7% 7% 42% 25% 16% 3	270
	11th to 20th	Day	8% 9% 41% 28% 11% 2	270
	21st to end	Day	13% 10% 38% 26% 11% 3	270
December	1st to 10th	Day	7% 9% 44% 31% 8% 1	270
	11th to 20th	Day	12% 13% 35% 31% 9%	270
	21st to end	Day	14% 14% 39% 27% 5% 1	297
January	1st to 10th	Night	8% 9% 39% 35% 8%	950
	11th to 20th	Night	7% 11% 42% 32% 7% 1	950
	21st to end	Night	7% 8% 45% 33% 6%	1045
February	1st to 10th	Night	11% 10% 45% 29% 5%	841
	11th to 20th	Night	7% 9% 47% 33% 4	744
	21st to end	Night	8% 11% 46% 31% 5%	628
March	1st to 10th	Night	11% 10% 40% 34% 4	760
	11th to 20th	Night	11% 9% 43% 32% 5%	627
	21st to end	Night	14% 9% 42% 29% 5%	627
April	1st to 10th	Night	16% 12% 43% 27% 1	570
	11th to 20th	Night	13% 15% 44% 26% 2	563
	21st to end	Night	16% 11% 34% 31% 8%	570
May	1st to 10th	Night	14% 8% 38% 31% 8%	570
	11th to 20th	Night	16% 8% 35% 33% 7% 1	561
	21st to end	Night	16% 8% 35% 32% 9%	617
June	1st to 10th	Night	6% 6% 32% 42% 13% 1	570
	11th to 20th	Night	11% 7% 39% 33% 9%	570
	21st to end	Night	5% 4 32% 49% 9%	570
July	1st to 10th	Night	5% 4 31% 44% 15%	555
	11th to 20th	Night	3 2 29% 52% 13% 1	552
	21st to end	Night	4 2 23% 54% 17%	624
August	1st to 10th	Night	5% 3 21% 55% 17%	567
	11th to 20th	Night	6% 3 26% 52% 13%	564
	21st to end	Night	4 2 29% 49% 15% 1	627
September	1st to 10th	Night	8% 3 29% 47% 13% 1	570
	11th to 20th	Night	8% 4 31% 43% 13% 1	570
	21st to end	Night	10% 6% 32% 38% 13% 1	570
October	1st to 10th	Night	14% 6% 31% 37% 11%	570
	11th to 20th	Night	10% 10% 32% 37% 10% 1	735
	21st to end	Night	12% 10% 35% 33% 10% 1	1015
November	1st to 10th	Night	6% 6% 41% 38% 8% 1	925
	11th to 20th	Night	8% 8% 40% 36% 7%	950
	21st to end	Night	8% 7% 36% 37% 11%	950
December	1st to 10th	Night	9% 10% 41% 34% 5%	950
	11th to 20th	Night	10% 9% 38% 35% 7%	950
	21st to end	Night	14% 11% 34% 36% 5%	1045

Page generated at 2024-10-22 19:21:02. Version ac07

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