Scottsbluff
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Scottsbluff clear sky chart from 2005-11-06 to 2024-03-08.

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	7% 5% 2 4 4 3 4 4 6% 8% 54%	78529
	Night	7% 5% 2 4 4 3 4 4 5% 7% 53%	81096
Transparency	Day	28% 7% 14% 26% 19% 6%	78233
	Night	29% 7% 15% 27% 18% 4	80914
Seeing	Day	10% 8% 27% 31% 19% 5%	14766
	Night	9% 7% 34% 39% 10%	24953

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	2 6% 4 7% 6% 3 3 4 5% 6% 54%	2538
	11th to 20th	Day	4 8% 4 7% 6% 4 4 6% 6% 7% 43%	2540
	21st to end	Day	3 5% 2 3 3 2 3 4 4 7% 63%	2926
February	1st to 10th	Day	5% 9% 4 7% 6% 4 4 4 5% 7% 45%	1714
	11th to 20th	Day	6% 7% 4 5% 4 3 5% 4 6% 7% 49%	1849
	21st to end	Day	5% 6% 3 6% 5% 3 4 4 5% 6% 53%	1570
March	1st to 10th	Day	5% 7% 2 4 5% 3 4 5% 5% 7% 52%	1870
	11th to 20th	Day	7% 6% 2 4 5% 3 5% 5% 5% 7% 52%	1850
	21st to end	Day	9% 6% 3 4 5% 3 4 5% 6% 8% 45%	2376
April	1st to 10th	Day	11% 6% 3 4 4 2 5% 4 6% 6% 49%	2160
	11th to 20th	Day	15% 6% 2 5% 4 2 5% 5% 5% 8% 43%	2131
	21st to end	Day	12% 6% 2 4 5% 3 4 4 6% 7% 46%	2228
May	1st to 10th	Day	14% 5% 2 4 4 3 5% 4 5% 7% 46%	2340
	11th to 20th	Day	15% 5% 2 5% 5% 3 5% 5% 5% 9% 40%	2460
	21st to end	Day	10% 5% 2 4 5% 2 6% 6% 7% 10% 43%	2724
June	1st to 10th	Day	7% 3 1 3 4 3 4 6% 6% 9% 54%	2520
	11th to 20th	Day	8% 3 2 3 4 2 4 5% 6% 9% 53%	2520
	21st to end	Day	4 2 1 3 4 3 4 5% 6% 9% 60%	2520
July	1st to 10th	Day	7% 3 1 3 3 2 5% 5% 8% 8% 54%	2520
	11th to 20th	Day	5% 2 1 3 3 2 4 4 7% 9% 61%	2520
	21st to end	Day	5% 2 2 4 4 3 5% 5% 7% 10% 54%	2742
August	1st to 10th	Day	4 3 2 4 4 3 5% 6% 7% 10% 54%	2463
	11th to 20th	Day	4 2 1 3 3 2 4 5% 5% 8% 62%	2123
	21st to end	Day	5% 3 1 3 3 2 5% 5% 5% 8% 62%	2376
September	1st to 10th	Day	7% 3 1 2 3 2 3 3 5% 5% 64%	2160
	11th to 20th	Day	8% 2 1 3 3 2 3 4 4 6% 65%	2086
	21st to end	Day	8% 3 1 2 3 2 2 3 5% 6% 64%	1980
October	1st to 10th	Day	12% 5% 1 3 3 2 3 3 5% 7% 57%	1895
	11th to 20th	Day	8% 3 2 3 3 2 3 3 5% 7% 62%	1800
	21st to end	Day	7% 5% 1 3 3 2 3 4 5% 6% 60%	1797
November	1st to 10th	Day	4 5% 2 3 4 2 3 4 5% 8% 59%	1673
	11th to 20th	Day	4 5% 2 3 3 2 4 4 6% 8% 59%	1710
	21st to end	Day	5% 6% 2 4 3 2 3 4 4 7% 60%	1608
December	1st to 10th	Day	5% 6% 3 5% 5% 3 4 4 6% 7% 53%	1520
	11th to 20th	Day	4 5% 1 4 4 3 3 4 6% 8% 57%	1926
	21st to end	Day	9% 10% 3 5% 4 3 3 4 4 7% 48%	2794
January	1st to 10th	Night	3 7% 3 5% 5% 3 4 4 5% 7% 53%	4417
	11th to 20th	Night	2 6% 4 7% 5% 3 4 5% 6% 8% 49%	4430
	21st to end	Night	3 4 2 5% 5% 3 4 5% 5% 7% 57%	4768
February	1st to 10th	Night	4 10% 3 7% 5% 4 4 5% 6% 6% 47%	2464
	11th to 20th	Night	6% 7% 3 6% 5% 3 5% 5% 6% 8% 47%	2218
	21st to end	Night	4 7% 3 7% 5% 3 4 3 5% 7% 52%	1884
March	1st to 10th	Night	6% 8% 3 4 4 3 4 4 4 7% 53%	2250
	11th to 20th	Night	8% 6% 2 5% 4 2 3 5% 5% 7% 53%	2106
	21st to end	Night	10% 7% 2 6% 5% 3 5% 4 6% 7% 45%	1980
April	1st to 10th	Night	13% 6% 2 4 4 3 4 4 5% 7% 48%	1800
	11th to 20th	Night	12% 6% 2 6% 5% 3 4 4 5% 6% 47%	1777
	21st to end	Night	13% 7% 3 5% 5% 3 4 4 5% 6% 44%	1729
May	1st to 10th	Night	15% 6% 2 6% 4 3 4 3 5% 7% 45%	1620
	11th to 20th	Night	17% 6% 2 3 4 3 4 5% 4 7% 45%	1433
	21st to end	Night	13% 4 2 3 6% 3 5% 5% 7% 9% 44%	1552
June	1st to 10th	Night	8% 4 2 4 3 3 5% 4 6% 10% 52%	1440
	11th to 20th	Night	8% 3 1 3 5% 3 4 5% 6% 11% 52%	1440
	21st to end	Night	4 2 1 3 4 4 4 5% 6% 11% 56%	1440
July	1st to 10th	Night	7% 3 2 4 4 3 6% 6% 6% 9% 51%	1440
	11th to 20th	Night	4 2 1 2 3 2 4 5% 7% 9% 61%	1440
	21st to end	Night	4 2 2 3 4 3 5% 7% 6% 10% 53%	1576
August	1st to 10th	Night	7% 3 1 3 4 3 6% 6% 7% 10% 51%	1472
	11th to 20th	Night	4 2 1 2 4 2 4 4 6% 9% 61%	1778
	21st to end	Night	4 3 1 4 4 3 5% 4 6% 8% 59%	1980
September	1st to 10th	Night	7% 4 2 3 4 2 4 4 4 7% 59%	1800
	11th to 20th	Night	8% 3 2 3 4 2 3 4 4 7% 61%	1873
	21st to end	Night	9% 3 1 3 4 2 4 4 4 4 62%	1980
October	1st to 10th	Night	12% 4 1 3 3 3 3 3 4 7% 57%	2061
	11th to 20th	Night	9% 4 1 3 3 2 3 4 5% 5% 62%	2160
	21st to end	Night	8% 6% 2 4 3 2 4 4 5% 7% 56%	2540
November	1st to 10th	Night	6% 4 2 5% 3 2 4 3 5% 8% 58%	2405
	11th to 20th	Night	5% 5% 2 5% 3 2 3 4 6% 7% 58%	2470
	21st to end	Night	5% 7% 2 4 3 2 3 4 5% 6% 58%	2569
December	1st to 10th	Night	5% 6% 2 5% 5% 2 4 4 5% 8% 53%	2660
	11th to 20th	Night	4 4 2 4 3 3 4 4 5% 8% 58%	3271
	21st to end	Night	10% 8% 3 5% 4 2 4 4 5% 7% 47%	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	30% 6% 14% 29% 20% 1	2539
	11th to 20th	Day	37% 9% 18% 20% 15% 1	2540
	21st to end	Day	21% 6% 21% 34% 14% 3	2926
February	1st to 10th	Day	39% 7% 16% 22% 14% 2	1714
	11th to 20th	Day	34% 7% 12% 26% 17% 4	1859
	21st to end	Day	31% 7% 14% 27% 17% 5%	1570
March	1st to 10th	Day	30% 6% 13% 28% 20% 4	1870
	11th to 20th	Day	32% 7% 14% 22% 21% 4	1850
	21st to end	Day	36% 9% 14% 27% 12% 2	2376
April	1st to 10th	Day	34% 7% 16% 25% 13% 5%	2160
	11th to 20th	Day	38% 8% 13% 22% 15% 4	2134
	21st to end	Day	34% 7% 12% 27% 17% 2	2228
May	1st to 10th	Day	36% 8% 15% 29% 11% 1	2340
	11th to 20th	Day	40% 9% 16% 25% 9% 1	2464
	21st to end	Day	34% 10% 18% 24% 13% 2	2724
June	1st to 10th	Day	24% 11% 17% 28% 16% 4	2520
	11th to 20th	Day	26% 8% 12% 27% 20% 7%	2520
	21st to end	Day	19% 7% 12% 26% 27% 9%	2520
July	1st to 10th	Day	25% 8% 12% 24% 24% 8%	2451
	11th to 20th	Day	18% 6% 11% 25% 26% 15%	2445
	21st to end	Day	23% 8% 15% 24% 22% 8%	2590
August	1st to 10th	Day	23% 9% 17% 26% 16% 9%	2447
	11th to 20th	Day	20% 7% 13% 27% 24% 10%	2123
	21st to end	Day	21% 6% 9% 23% 28% 13%	2376
September	1st to 10th	Day	22% 4 8% 21% 29% 16%	2160
	11th to 20th	Day	21% 4 9% 24% 28% 14%	2086
	21st to end	Day	21% 4 10% 26% 33% 6%	1980
October	1st to 10th	Day	28% 5% 12% 23% 26% 6%	1895
	11th to 20th	Day	24% 5% 11% 29% 24% 8%	1800
	21st to end	Day	24% 6% 14% 29% 21% 7%	1797
November	1st to 10th	Day	23% 5% 16% 27% 21% 8%	1673
	11th to 20th	Day	22% 5% 15% 30% 24% 4	1710
	21st to end	Day	25% 4 14% 29% 24% 4	1608
December	1st to 10th	Day	29% 7% 16% 27% 18% 3	1520
	11th to 20th	Day	24% 6% 15% 36% 18% 1	1924
	21st to end	Day	36% 6% 12% 30% 14% 2	2794
January	1st to 10th	Night	29% 7% 12% 36% 14% 1	4417
	11th to 20th	Night	30% 8% 21% 22% 17% 3	4430
	21st to end	Night	25% 8% 21% 32% 13% 1	4768
February	1st to 10th	Night	36% 8% 16% 26% 13% 2	2464
	11th to 20th	Night	34% 8% 14% 25% 15% 3	2218
	21st to end	Night	33% 6% 12% 28% 18% 4	1884
March	1st to 10th	Night	31% 6% 11% 28% 19% 4	2250
	11th to 20th	Night	30% 6% 13% 26% 21% 4	2106
	21st to end	Night	37% 7% 18% 22% 14% 1	1980
April	1st to 10th	Night	35% 7% 13% 23% 17% 5%	1800
	11th to 20th	Night	36% 8% 14% 24% 15% 3	1777
	21st to end	Night	39% 8% 10% 26% 15% 1	1729
May	1st to 10th	Night	40% 7% 15% 24% 13% 1	1620
	11th to 20th	Night	38% 9% 17% 26% 9% 1	1434
	21st to end	Night	35% 11% 19% 22% 10% 3	1552
June	1st to 10th	Night	27% 10% 24% 24% 12% 3	1440
	11th to 20th	Night	25% 9% 19% 24% 17% 7%	1440
	21st to end	Night	21% 8% 16% 26% 23% 5%	1440
July	1st to 10th	Night	27% 8% 15% 28% 17% 5%	1400
	11th to 20th	Night	18% 7% 14% 26% 22% 12%	1392
	21st to end	Night	22% 9% 18% 28% 17% 6%	1488
August	1st to 10th	Night	25% 11% 20% 24% 15% 5%	1464
	11th to 20th	Night	19% 6% 16% 26% 22% 11%	1778
	21st to end	Night	23% 7% 12% 22% 26% 11%	1980
September	1st to 10th	Night	26% 5% 9% 23% 25% 12%	1800
	11th to 20th	Night	22% 7% 10% 26% 24% 12%	1873
	21st to end	Night	25% 5% 7% 29% 24% 9%	1980
October	1st to 10th	Night	29% 6% 13% 22% 25% 6%	2061
	11th to 20th	Night	24% 5% 12% 28% 21% 10%	2160
	21st to end	Night	28% 6% 13% 25% 20% 8%	2540
November	1st to 10th	Night	25% 6% 13% 27% 24% 6%	2405
	11th to 20th	Night	25% 6% 12% 30% 21% 6%	2470
	21st to end	Night	27% 6% 11% 30% 21% 5%	2569
December	1st to 10th	Night	29% 6% 15% 29% 18% 4	2660
	11th to 20th	Night	25% 5% 15% 37% 17% 1	3272
	21st to end	Night	35% 7% 13% 30% 13% 2	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% 6% 33% 32% 16% 3	270
	11th to 20th	Day	10% 13% 34% 33% 9%	270
	21st to end	Day	8% 9% 47% 27% 7% 2	297
February	1st to 10th	Day	8% 16% 49% 22% 5%	270
	11th to 20th	Day	7% 16% 46% 24% 6% 2	270
	21st to end	Day	14% 16% 37% 29% 4	225
March	1st to 10th	Day	7% 15% 35% 30% 13%	261
	11th to 20th	Day	12% 10% 36% 28% 11% 3	290
	21st to end	Day	13% 15% 35% 26% 9% 2	462
April	1st to 10th	Day	16% 16% 34% 23% 10% 1	420
	11th to 20th	Day	21% 17% 31% 22% 7% 2	412
	21st to end	Day	15% 13% 29% 27% 14% 3	488
May	1st to 10th	Day	16% 12% 24% 30% 15% 3	603
	11th to 20th	Day	18% 7% 22% 32% 16% 5%	625
	21st to end	Day	14% 9% 26% 29% 19% 4	679
June	1st to 10th	Day	6% 4 21% 35% 26% 8%	630
	11th to 20th	Day	9% 6% 29% 36% 18% 3	630
	21st to end	Day	6% 5% 25% 33% 28% 4	630
July	1st to 10th	Day	7% 1 17% 38% 30% 6%	621
	11th to 20th	Day	5% 2 19% 36% 32% 7%	618
	21st to end	Day	6% 2 14% 37% 37% 5%	684
August	1st to 10th	Day	5% 2 18% 38% 32% 5%	599
	11th to 20th	Day	5% 4 17% 37% 26% 11%	437
	21st to end	Day	4 3 23% 32% 25% 12%	495
September	1st to 10th	Day	5% 5% 21% 31% 28% 10%	450
	11th to 20th	Day	7% 2 19% 31% 29% 12%	376
	21st to end	Day	7% 9% 21% 32% 20% 11%	270
October	1st to 10th	Day	15% 6% 23% 23% 21% 12%	270
	11th to 20th	Day	9% 13% 29% 27% 16% 7%	270
	21st to end	Day	10% 11% 31% 28% 16% 4	297
November	1st to 10th	Day	6% 10% 31% 34% 14% 5%	270
	11th to 20th	Day	6% 12% 33% 33% 15% 1	270
	21st to end	Day	13% 7% 33% 33% 13% 2	270
December	1st to 10th	Day	9% 12% 38% 30% 10% 1	270
	11th to 20th	Day	9% 13% 42% 26% 10%	270
	21st to end	Day	14% 11% 37% 29% 8% 1	297
January	1st to 10th	Night	7% 10% 38% 34% 10%	950
	11th to 20th	Night	7% 13% 42% 31% 6% 1	950
	21st to end	Night	8% 8% 45% 33% 6%	979
February	1st to 10th	Night	8% 9% 49% 29% 5%	760
	11th to 20th	Night	9% 9% 43% 34% 5%	744
	21st to end	Night	8% 12% 45% 31% 4	628
March	1st to 10th	Night	10% 10% 40% 35% 6%	750
	11th to 20th	Night	12% 6% 35% 39% 7%	720
	21st to end	Night	14% 11% 36% 35% 5%	594
April	1st to 10th	Night	16% 11% 36% 32% 5%	540
	11th to 20th	Night	13% 10% 39% 33% 4	533
	21st to end	Night	17% 9% 30% 35% 9%	540
May	1st to 10th	Night	18% 7% 30% 35% 10% 1	540
	11th to 20th	Night	17% 6% 26% 40% 11%	531
	21st to end	Night	13% 5% 31% 39% 12%	584
June	1st to 10th	Night	9% 5% 26% 44% 16% 1	540
	11th to 20th	Night	8% 5% 33% 46% 8%	540
	21st to end	Night	4 2 28% 54% 11%	540
July	1st to 10th	Night	7% 2 20% 51% 20% 1	525
	11th to 20th	Night	5% 1 21% 56% 17%	522
	21st to end	Night	4 1 18% 54% 23%	591
August	1st to 10th	Night	7% 1 22% 50% 19%	537
	11th to 20th	Night	4 2 24% 53% 16%	534
	21st to end	Night	4 3 20% 55% 19%	594
September	1st to 10th	Night	9% 3 24% 47% 17% 1	540
	11th to 20th	Night	9% 3 21% 46% 19% 1	540
	21st to end	Night	10% 2 29% 45% 13% 1	540
October	1st to 10th	Night	15% 5% 27% 38% 13% 1	621
	11th to 20th	Night	11% 6% 32% 39% 12%	720
	21st to end	Night	12% 6% 34% 37% 10%	956
November	1st to 10th	Night	7% 6% 36% 41% 10%	925
	11th to 20th	Night	6% 10% 41% 36% 6%	950
	21st to end	Night	8% 8% 35% 39% 8%	950
December	1st to 10th	Night	8% 10% 45% 32% 5%	950
	11th to 20th	Night	8% 7% 40% 39% 5%	950
	21st to end	Night	12% 11% 40% 32% 6%	1045

Page generated at 2024-03-05 05:24:02. Version ac07

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