Pawnee Buttes Trailhead
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pawnee Buttes Trailhead clear sky chart from 2005-11-06 to 2024-11-30.

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	5% 5% 2 5% 4 4 4 4 6% 8% 54%	105404
	Night	6% 6% 2 6% 4 4 4 4 6% 7% 52%	102915
Transparency	Day	26% 7% 12% 25% 21% 9%	105145
	Night	29% 7% 13% 25% 20% 7%	102764
Seeing	Day	9% 9% 28% 31% 19% 5%	15779
	Night	9% 9% 32% 37% 12% 1	25794

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 7% 3 6% 4 4 3 3 4 6% 58%	2538
	11th to 20th	Day	2 8% 3 9% 6% 5% 4 4 6% 7% 45%	2540
	21st to end	Day	2 5% 2 5% 3 3 3 4 5% 7% 61%	3027
February	1st to 10th	Day	2 8% 4 10% 6% 4 4 3 5% 7% 46%	1726
	11th to 20th	Day	3 8% 2 7% 4 4 5% 4 6% 7% 51%	1849
	21st to end	Day	2 9% 3 7% 4 4 4 4 5% 6% 52%	1570
March	1st to 10th	Day	4 9% 3 6% 4 4 4 3 6% 7% 51%	3130
	11th to 20th	Day	5% 7% 3 6% 3 4 4 3 5% 6% 55%	3314
	21st to end	Day	5% 8% 2 7% 4 5% 5% 4 6% 9% 44%	4151
April	1st to 10th	Day	8% 7% 2 5% 4 4 4 4 6% 6% 49%	2280
	11th to 20th	Day	12% 8% 2 6% 4 4 4 4 6% 7% 42%	2251
	21st to end	Day	11% 7% 2 6% 4 5% 4 4 5% 8% 44%	2308
May	1st to 10th	Day	11% 7% 2 7% 5% 5% 5% 4 5% 7% 42%	4120
	11th to 20th	Day	8% 4 2 5% 4 4 5% 5% 7% 10% 45%	4319
	21st to end	Day	8% 5% 1 4 4 4 5% 4 7% 8% 49%	4825
June	1st to 10th	Day	6% 3 1 3 3 3 4 5% 8% 10% 53%	2660
	11th to 20th	Day	6% 4 2 4 4 3 5% 4 6% 9% 53%	2660
	21st to end	Day	4 2 1 4 3 4 5% 4 8% 9% 56%	2660
July	1st to 10th	Day	7% 4 1 4 3 3 4 4 6% 7% 55%	4430
	11th to 20th	Day	2 2 1 4 4 4 5% 5% 8% 10% 54%	4430
	21st to end	Day	3 2 1 4 4 5% 5% 5% 7% 9% 56%	4802
August	1st to 10th	Day	10% 4 1 3 3 4 5% 4 8% 10% 47%	4178
	11th to 20th	Day	4 3 1 4 3 4 5% 4 7% 9% 54%	3726
	21st to end	Day	4 3 1 4 3 3 4 4 6% 8% 58%	4180
September	1st to 10th	Day	5% 3 1 4 3 3 3 3 5% 8% 61%	2280
	11th to 20th	Day	6% 2 1 3 3 3 3 3 5% 8% 63%	2213
	21st to end	Day	7% 4 1 3 2 3 3 2 4 6% 65%	2090
October	1st to 10th	Day	6% 3 1 2 2 2 2 2 3 4 75%	3306
	11th to 20th	Day	4 4 2 5% 3 3 3 2 4 6% 64%	3150
	21st to end	Day	8% 6% 2 4 2 2 3 3 5% 8% 59%	3168
November	1st to 10th	Day	3 5% 2 4 3 3 4 3 5% 7% 61%	1763
	11th to 20th	Day	3 7% 1 4 3 3 3 4 5% 7% 60%	1800
	21st to end	Day	3 6% 2 5% 3 3 3 3 4 7% 59%	1720
December	1st to 10th	Day	3 6% 3 8% 4 4 5% 4 5% 7% 54%	1520
	11th to 20th	Day	3 8% 3 6% 3 4 4 4 5% 6% 54%	1926
	21st to end	Day	4 8% 3 7% 4 5% 4 4 5% 8% 48%	2794
January	1st to 10th	Night	3 6% 3 7% 4 3 4 3 6% 7% 54%	4417
	11th to 20th	Night	2 6% 3 8% 4 5% 4 4 7% 7% 50%	4430
	21st to end	Night	3 6% 3 7% 4 4 4 3 5% 6% 56%	4669
February	1st to 10th	Night	3 8% 4 7% 5% 4 4 4 5% 7% 48%	2452
	11th to 20th	Night	4 7% 4 6% 5% 4 5% 4 6% 7% 49%	2218
	21st to end	Night	3 8% 3 6% 4 4 5% 3 4 5% 55%	1884
March	1st to 10th	Night	3 10% 3 7% 3 3 3 3 5% 5% 53%	3734
	11th to 20th	Night	9% 10% 3 6% 4 3 3 3 4 5% 51%	3659
	21st to end	Night	7% 8% 3 6% 4 5% 4 4 6% 8% 45%	3491
April	1st to 10th	Night	8% 8% 2 6% 4 4 4 3 6% 5% 49%	1900
	11th to 20th	Night	13% 6% 3 6% 5% 4 3 3 5% 5% 46%	1877
	21st to end	Night	14% 9% 2 6% 3 4 4 4 6% 6% 42%	1872
May	1st to 10th	Night	11% 6% 3 7% 5% 5% 6% 5% 6% 8% 39%	2850
	11th to 20th	Night	11% 5% 2 6% 3 4 5% 4 6% 10% 44%	2582
	21st to end	Night	11% 6% 2 6% 4 5% 5% 4 7% 8% 41%	2762
June	1st to 10th	Night	6% 4 1 4 3 4 3 5% 9% 11% 50%	1520
	11th to 20th	Night	7% 4 2 3 5% 2 5% 4 5% 9% 53%	1520
	21st to end	Night	6% 4 2 5% 4 5% 4 5% 7% 9% 50%	1520
July	1st to 10th	Night	5% 4 2 5% 4 4 5% 4 6% 8% 52%	2540
	11th to 20th	Night	3 3 1 4 4 4 5% 5% 8% 11% 52%	2540
	21st to end	Night	4 4 2 4 4 4 5% 4 8% 10% 52%	2761
August	1st to 10th	Night	13% 5% 1 6% 5% 6% 5% 5% 8% 9% 37%	2755
	11th to 20th	Night	4 6% 2 7% 5% 5% 5% 4 7% 9% 45%	3113
	21st to end	Night	3 4 1 4 4 5% 5% 5% 9% 10% 50%	3487
September	1st to 10th	Night	6% 5% 2 5% 3 4 4 5% 5% 8% 54%	1900
	11th to 20th	Night	7% 3 2 4 3 3 3 3 5% 7% 59%	1966
	21st to end	Night	6% 3 1 4 3 3 3 2 4 5% 63%	2090
October	1st to 10th	Night	6% 2 1 3 2 2 2 2 4 5% 71%	3657
	11th to 20th	Night	8% 4 1 5% 3 3 3 3 5% 7% 58%	3778
	21st to end	Night	6% 5% 2 4 3 3 3 3 4 6% 60%	4358
November	1st to 10th	Night	4 4 2 5% 4 3 3 3 6% 7% 58%	2535
	11th to 20th	Night	4 6% 2 4 4 4 3 3 5% 7% 59%	2600
	21st to end	Night	4 7% 2 5% 3 4 4 3 6% 6% 57%	2674
December	1st to 10th	Night	3 6% 2 6% 4 4 3 4 5% 7% 55%	2660
	11th to 20th	Night	4 5% 2 5% 3 4 4 4 6% 7% 56%	3271
	21st to end	Night	5% 7% 3 7% 4 4 4 4 6% 8% 48%	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	27% 5% 12% 31% 21% 4	2539
	11th to 20th	Day	34% 8% 18% 22% 14% 4	2540
	21st to end	Day	22% 6% 18% 32% 19% 4	3027
February	1st to 10th	Day	37% 4 13% 24% 16% 5%	1726
	11th to 20th	Day	31% 5% 10% 29% 19% 5%	1859
	21st to end	Day	32% 4 9% 27% 21% 7%	1570
March	1st to 10th	Day	28% 5% 11% 20% 28% 7%	3130
	11th to 20th	Day	28% 7% 14% 33% 15% 3	3314
	21st to end	Day	32% 10% 15% 31% 10% 2	4151
April	1st to 10th	Day	31% 8% 13% 24% 17% 7%	2280
	11th to 20th	Day	39% 7% 12% 21% 15% 6%	2254
	21st to end	Day	36% 7% 10% 28% 18% 2	2308
May	1st to 10th	Day	37% 10% 12% 24% 13% 5%	4120
	11th to 20th	Day	28% 11% 15% 28% 16% 2	4323
	21st to end	Day	27% 10% 17% 26% 18% 3	4825
June	1st to 10th	Day	22% 8% 19% 28% 16% 7%	2660
	11th to 20th	Day	26% 6% 11% 24% 23% 10%	2660
	21st to end	Day	21% 7% 12% 25% 25% 11%	2660
July	1st to 10th	Day	26% 7% 9% 17% 28% 14%	4361
	11th to 20th	Day	20% 7% 13% 24% 21% 15%	4355
	21st to end	Day	22% 7% 10% 20% 19% 21%	4651
August	1st to 10th	Day	28% 8% 14% 26% 17% 7%	4163
	11th to 20th	Day	24% 8% 11% 21% 23% 12%	3762
	21st to end	Day	21% 6% 10% 21% 27% 15%	4179
September	1st to 10th	Day	20% 4 8% 23% 28% 16%	2280
	11th to 20th	Day	21% 5% 8% 21% 29% 16%	2213
	21st to end	Day	22% 4 7% 22% 34% 11%	2090
October	1st to 10th	Day	16% 3 6% 18% 32% 26%	3306
	11th to 20th	Day	23% 4 9% 29% 26% 9%	3150
	21st to end	Day	24% 3 9% 26% 29% 8%	3168
November	1st to 10th	Day	23% 4 12% 27% 25% 9%	1763
	11th to 20th	Day	23% 4 9% 27% 29% 8%	1800
	21st to end	Day	25% 5% 9% 26% 27% 8%	1720
December	1st to 10th	Day	29% 6% 13% 28% 19% 5%	1520
	11th to 20th	Day	28% 6% 10% 28% 25% 3	1924
	21st to end	Day	34% 6% 11% 28% 18% 3	2794
January	1st to 10th	Night	27% 6% 12% 31% 20% 3	4417
	11th to 20th	Night	28% 9% 15% 23% 19% 7%	4430
	21st to end	Night	28% 7% 15% 32% 15% 3	4669
February	1st to 10th	Night	35% 5% 13% 24% 18% 4	2452
	11th to 20th	Night	32% 6% 13% 25% 20% 4	2218
	21st to end	Night	31% 4 10% 23% 24% 8%	1884
March	1st to 10th	Night	31% 6% 9% 19% 29% 7%	3734
	11th to 20th	Night	34% 6% 14% 22% 22% 3	3659
	21st to end	Night	33% 10% 17% 28% 10% 1	3491
April	1st to 10th	Night	35% 6% 11% 24% 18% 6%	1900
	11th to 20th	Night	38% 6% 13% 23% 15% 4	1877
	21st to end	Night	40% 8% 10% 23% 18% 2	1872
May	1st to 10th	Night	37% 11% 17% 23% 9% 4	2850
	11th to 20th	Night	31% 12% 19% 26% 9% 3	2583
	21st to end	Night	36% 11% 19% 18% 12% 4	2762
June	1st to 10th	Night	24% 11% 23% 26% 13% 4	1520
	11th to 20th	Night	28% 7% 14% 24% 18% 10%	1520
	21st to end	Night	28% 8% 13% 26% 21% 5%	1520
July	1st to 10th	Night	27% 7% 13% 21% 25% 6%	2500
	11th to 20th	Night	22% 8% 17% 21% 25% 7%	2492
	21st to end	Night	23% 8% 14% 25% 19% 11%	2674
August	1st to 10th	Night	39% 9% 17% 20% 13% 3	2747
	11th to 20th	Night	33% 9% 14% 20% 16% 8%	3143
	21st to end	Night	24% 7% 16% 22% 21% 9%	3487
September	1st to 10th	Night	26% 7% 9% 21% 24% 13%	1900
	11th to 20th	Night	23% 5% 10% 25% 24% 13%	1966
	21st to end	Night	22% 5% 8% 25% 27% 12%	2090
October	1st to 10th	Night	17% 4 7% 19% 28% 25%	3657
	11th to 20th	Night	25% 5% 10% 30% 23% 8%	3778
	21st to end	Night	25% 4 9% 28% 23% 11%	4358
November	1st to 10th	Night	24% 6% 12% 24% 26% 9%	2535
	11th to 20th	Night	25% 4 10% 26% 25% 9%	2600
	21st to end	Night	28% 4 10% 25% 26% 7%	2674
December	1st to 10th	Night	27% 6% 14% 29% 18% 7%	2660
	11th to 20th	Night	25% 5% 10% 32% 24% 3	3272
	21st to end	Night	33% 6% 12% 28% 18% 4	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	6% 11% 29% 37% 13% 4	270
	11th to 20th	Day	10% 13% 40% 29% 7% 1	270
	21st to end	Day	6% 13% 48% 23% 9% 1	297
February	1st to 10th	Day	6% 18% 44% 27% 4 1	270
	11th to 20th	Day	9% 13% 44% 26% 7% 1	270
	21st to end	Day	7% 19% 43% 28% 4	225
March	1st to 10th	Day	7% 14% 33% 28% 15% 2	270
	11th to 20th	Day	11% 14% 30% 31% 13% 2	349
	21st to end	Day	13% 15% 38% 26% 8% 1	506
April	1st to 10th	Day	14% 17% 38% 22% 8% 1	460
	11th to 20th	Day	17% 19% 32% 22% 7% 2	452
	21st to end	Day	15% 18% 28% 25% 11% 3	488
May	1st to 10th	Day	16% 13% 27% 29% 12% 3	653
	11th to 20th	Day	15% 7% 25% 29% 19% 4	675
	21st to end	Day	12% 9% 28% 27% 20% 5%	734
June	1st to 10th	Day	5% 7% 20% 35% 23% 10%	680
	11th to 20th	Day	8% 6% 30% 35% 17% 4	680
	21st to end	Day	4 4 27% 36% 22% 5%	680
July	1st to 10th	Day	8% 3 15% 33% 32% 9%	671
	11th to 20th	Day	4 1 18% 34% 34% 9%	668
	21st to end	Day	4 2 15% 34% 35% 10%	739
August	1st to 10th	Day	6% 3 14% 37% 32% 7%	577
	11th to 20th	Day	3 4 21% 35% 26% 11%	477
	21st to end	Day	5% 3 21% 35% 28% 8%	539
September	1st to 10th	Day	6% 3 21% 37% 24% 10%	490
	11th to 20th	Day	5% 4 21% 31% 30% 10%	423
	21st to end	Day	11% 4 24% 29% 21% 11%	300
October	1st to 10th	Day	11% 6% 27% 22% 25% 10%	300
	11th to 20th	Day	6% 9% 37% 28% 13% 7%	300
	21st to end	Day	12% 12% 30% 30% 12% 3	330
November	1st to 10th	Day	6% 11% 32% 31% 15% 4	300
	11th to 20th	Day	6% 14% 37% 30% 11% 2	300
	21st to end	Day	8% 9% 31% 39% 11% 2	299
December	1st to 10th	Day	9% 15% 36% 30% 11%	270
	11th to 20th	Day	11% 13% 44% 26% 7%	270
	21st to end	Day	8% 15% 39% 28% 8% 1	297
January	1st to 10th	Night	6% 13% 36% 33% 10% 1	950
	11th to 20th	Night	5% 16% 41% 30% 7% 1	950
	21st to end	Night	7% 10% 45% 31% 7% 1	919
February	1st to 10th	Night	8% 11% 45% 28% 7%	760
	11th to 20th	Night	6% 12% 44% 32% 6%	744
	21st to end	Night	7% 13% 48% 28% 4	628
March	1st to 10th	Night	7% 10% 39% 36% 8%	760
	11th to 20th	Night	10% 10% 34% 35% 10% 1	760
	21st to end	Night	11% 12% 39% 30% 7% 1	641
April	1st to 10th	Night	13% 15% 35% 31% 5% 1	570
	11th to 20th	Night	16% 11% 37% 30% 6% 1	563
	21st to end	Night	16% 13% 30% 32% 8% 1	570
May	1st to 10th	Night	16% 11% 30% 32% 11%	570
	11th to 20th	Night	18% 6% 26% 37% 12% 1	561
	21st to end	Night	12% 7% 33% 32% 14% 1	617
June	1st to 10th	Night	6% 5% 25% 43% 20% 1	570
	11th to 20th	Night	7% 7% 31% 44% 10% 1	570
	21st to end	Night	6% 3 26% 47% 17% 1	570
July	1st to 10th	Night	9% 2 17% 48% 24% 1	555
	11th to 20th	Night	5% 2 14% 53% 25% 2	552
	21st to end	Night	6% 2 13% 51% 27% 1	624
August	1st to 10th	Night	7% 3 15% 47% 26% 2	567
	11th to 20th	Night	4 2 18% 53% 22%	564
	21st to end	Night	6% 2 16% 50% 24% 1	627
September	1st to 10th	Night	8% 3 18% 50% 20% 2	570
	11th to 20th	Night	8% 4 20% 45% 20% 3	570
	21st to end	Night	8% 5% 28% 41% 18% 1	570
October	1st to 10th	Night	13% 8% 25% 33% 19% 2	669
	11th to 20th	Night	8% 7% 35% 33% 16% 1	760
	21st to end	Night	10% 11% 30% 37% 11% 1	973
November	1st to 10th	Night	6% 7% 36% 38% 11% 2	975
	11th to 20th	Night	7% 12% 36% 37% 7% 1	1000
	21st to end	Night	7% 10% 34% 39% 10% 1	1000
December	1st to 10th	Night	6% 13% 42% 33% 5%	950
	11th to 20th	Night	8% 11% 39% 34% 7% 1	950
	21st to end	Night	10% 13% 37% 33% 5%	1045

Page generated at 2024-11-27 15:30:54. Version ac07

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