Green River State Wildlife Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Green River State Wildlife Area clear sky chart from 2005-11-06 to 2024-11-02.

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	13% 9% 3 8% 5% 4 4 4 5% 7% 38%	101368
	Night	14% 9% 3 7% 4 4 4 3 5% 6% 39%	97693
Transparency	Day	45% 4 12% 24% 13% 2	101156
	Night	46% 3 11% 23% 14% 2	97577
Seeing	Day	16% 10% 27% 26% 15% 5%	15812
	Night	17% 9% 31% 30% 12% 1	25640

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% 11% 8% 16% 6% 6% 5% 3 5% 5% 24%	2527
	11th to 20th	Day	13% 12% 4 15% 7% 6% 6% 5% 9% 5% 18%	2530
	21st to end	Day	16% 20% 9% 13% 6% 4 4 3 3 5% 17%	3014
February	1st to 10th	Day	14% 15% 4 10% 5% 4 5% 3 5% 5% 28%	1710
	11th to 20th	Day	13% 11% 3 8% 5% 5% 4 3 5% 7% 35%	1810
	21st to end	Day	13% 14% 6% 11% 4 5% 4 3 4 6% 30%	1570
March	1st to 10th	Day	15% 13% 5% 6% 4 3 3 3 4 6% 38%	3120
	11th to 20th	Day	11% 7% 3 6% 5% 4 4 4 7% 6% 43%	3379
	21st to end	Day	20% 13% 4 12% 5% 5% 4 3 5% 6% 22%	4101
April	1st to 10th	Day	17% 13% 3 7% 4 4 4 3 5% 6% 33%	2280
	11th to 20th	Day	18% 9% 3 7% 5% 4 4 3 5% 6% 37%	2254
	21st to end	Day	21% 9% 2 7% 4 5% 4 4 4 6% 34%	2299
May	1st to 10th	Day	16% 7% 3 8% 5% 4 5% 4 4 8% 36%	4138
	11th to 20th	Day	16% 6% 2 7% 4 4 4 3 4 7% 42%	4399
	21st to end	Day	11% 6% 2 6% 4 4 5% 4 6% 9% 42%	4824
June	1st to 10th	Day	10% 5% 2 5% 5% 4 4 4 7% 8% 46%	2660
	11th to 20th	Day	10% 4 2 6% 4 4 5% 4 6% 9% 46%	2660
	21st to end	Day	12% 6% 2 6% 5% 4 6% 5% 7% 9% 38%	2660
July	1st to 10th	Day	10% 8% 3 8% 5% 5% 6% 5% 7% 8% 35%	4440
	11th to 20th	Day	7% 4 1 5% 3 3 4 4 6% 9% 52%	4440
	21st to end	Day	8% 6% 2 7% 5% 5% 5% 4 7% 10% 40%	4813
August	1st to 10th	Day	8% 4 2 6% 5% 4 5% 4 7% 10% 43%	4243
	11th to 20th	Day	11% 5% 2 5% 3 4 4 4 7% 10% 43%	3764
	21st to end	Day	8% 6% 2 5% 4 4 4 4 5% 9% 50%	4180
September	1st to 10th	Day	12% 5% 1 6% 4 3 4 3 5% 9% 47%	2280
	11th to 20th	Day	13% 3 1 4 3 3 3 3 5% 7% 55%	2218
	21st to end	Day	10% 7% 2 6% 4 4 4 4 5% 8% 47%	2090
October	1st to 10th	Day	13% 6% 2 5% 3 3 3 3 5% 6% 49%	1943
	11th to 20th	Day	16% 9% 3 7% 5% 4 4 3 5% 6% 40%	1900
	21st to end	Day	20% 10% 2 6% 4 3 3 3 4 5% 40%	1947
November	1st to 10th	Day	11% 8% 2 5% 4 4 4 4 5% 7% 46%	1681
	11th to 20th	Day	16% 12% 4 8% 4 4 5% 4 4 6% 33%	1710
	21st to end	Day	16% 12% 5% 8% 4 4 3 2 4 5% 36%	1563
December	1st to 10th	Day	14% 14% 4 9% 5% 4 4 3 4 6% 33%	1520
	11th to 20th	Day	13% 15% 4 10% 6% 6% 4 3 5% 5% 30%	1918
	21st to end	Day	21% 19% 10% 13% 6% 3 3 3 3 4 15%	2783
January	1st to 10th	Night	13% 14% 6% 13% 5% 5% 4 3 4 5% 30%	4428
	11th to 20th	Night	13% 17% 7% 13% 6% 4 4 4 7% 4 21%	4440
	21st to end	Night	19% 18% 7% 10% 5% 3 4 3 4 4 22%	4651
February	1st to 10th	Night	15% 13% 5% 9% 5% 4 4 3 4 5% 33%	2470
	11th to 20th	Night	13% 10% 3 7% 4 4 4 4 4 7% 39%	2256
	21st to end	Night	17% 12% 4 9% 5% 3 4 3 3 6% 36%	1884
March	1st to 10th	Night	18% 10% 2 5% 3 4 4 3 4 5% 41%	3733
	11th to 20th	Night	10% 6% 2 6% 5% 4 4 3 5% 6% 48%	3608
	21st to end	Night	23% 11% 5% 10% 5% 5% 4 3 4 5% 25%	3530
April	1st to 10th	Night	17% 12% 3 6% 3 5% 3 3 4 6% 38%	1900
	11th to 20th	Night	19% 9% 2 6% 3 3 3 3 4 5% 42%	1875
	21st to end	Night	16% 8% 3 8% 5% 4 4 4 6% 7% 35%	1879
May	1st to 10th	Night	17% 7% 3 7% 5% 5% 5% 5% 5% 8% 34%	2755
	11th to 20th	Night	13% 6% 3 7% 4 4 5% 4 6% 9% 40%	2506
	21st to end	Night	10% 7% 2 6% 4 3 4 4 6% 8% 47%	2743
June	1st to 10th	Night	9% 5% 2 6% 4 4 5% 5% 5% 8% 48%	1520
	11th to 20th	Night	9% 3 2 6% 4 3 5% 4 8% 9% 47%	1520
	21st to end	Night	9% 5% 2 5% 5% 5% 5% 5% 6% 7% 45%	1520
July	1st to 10th	Night	15% 6% 3 7% 4 5% 4 4 6% 7% 40%	2530
	11th to 20th	Night	6% 4 1 5% 3 4 4 3 6% 7% 58%	2530
	21st to end	Night	5% 4 2 7% 5% 5% 5% 5% 8% 8% 47%	2750
August	1st to 10th	Night	6% 4 2 4 4 4 4 4 6% 9% 53%	2694
	11th to 20th	Night	8% 5% 2 6% 4 4 4 3 5% 8% 52%	3065
	21st to end	Night	7% 4 2 5% 3 4 4 3 6% 9% 53%	3476
September	1st to 10th	Night	10% 5% 2 4 3 2 3 3 4 6% 58%	1900
	11th to 20th	Night	10% 4 2 4 4 4 4 4 5% 7% 53%	1942
	21st to end	Night	9% 5% 2 7% 3 4 4 4 6% 7% 48%	2090
October	1st to 10th	Night	11% 5% 2 6% 4 3 3 3 4 5% 54%	2232
	11th to 20th	Night	16% 7% 3 6% 4 3 3 2 4 5% 47%	2280
	21st to end	Night	19% 10% 2 6% 3 4 4 3 5% 6% 37%	2650
November	1st to 10th	Night	10% 8% 2 4 3 3 3 3 5% 5% 52%	2431
	11th to 20th	Night	14% 9% 4 8% 4 4 4 3 6% 6% 38%	2470
	21st to end	Night	17% 11% 3 7% 5% 4 3 3 4 6% 39%	2612
December	1st to 10th	Night	16% 12% 4 9% 5% 4 4 3 5% 6% 33%	2660
	11th to 20th	Night	15% 14% 5% 9% 4 4 4 3 4 5% 33%	3279
	21st to end	Night	21% 17% 6% 11% 6% 5% 5% 3 4 5% 17%	4884

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	63% 2 12% 16% 6%	2528
	11th to 20th	Day	65% 3 10% 13% 9% 1	2530
	21st to end	Day	72% 2 8% 13% 5%	3014
February	1st to 10th	Day	58% 2 12% 18% 9% 1	1710
	11th to 20th	Day	51% 3 11% 25% 10% 1	1820
	21st to end	Day	56% 3 10% 21% 9% 2	1570
March	1st to 10th	Day	50% 2 12% 21% 13% 2	3120
	11th to 20th	Day	41% 2 13% 31% 13% 1	3379
	21st to end	Day	63% 2 15% 17% 3 1	4101
April	1st to 10th	Day	52% 3 11% 23% 10%	2280
	11th to 20th	Day	49% 2 10% 24% 13% 2	2254
	21st to end	Day	52% 4 10% 20% 13% 2	2299
May	1st to 10th	Day	48% 3 11% 24% 14% 1	4176
	11th to 20th	Day	45% 3 9% 31% 13%	4403
	21st to end	Day	39% 3 11% 25% 17% 5%	4837
June	1st to 10th	Day	35% 3 14% 29% 17% 2	2660
	11th to 20th	Day	34% 4 11% 25% 23% 3	2660
	21st to end	Day	40% 6% 13% 25% 14% 2	2660
July	1st to 10th	Day	43% 6% 12% 25% 11% 2	4371
	11th to 20th	Day	27% 5% 17% 32% 17% 2	4365
	21st to end	Day	37% 7% 16% 19% 19% 2	4662
August	1st to 10th	Day	34% 6% 16% 30% 13% 1	4228
	11th to 20th	Day	34% 6% 14% 29% 16% 1	3800
	21st to end	Day	32% 5% 11% 33% 17% 2	4179
September	1st to 10th	Day	36% 4 10% 26% 20% 4	2280
	11th to 20th	Day	30% 4 10% 30% 23% 3	2218
	21st to end	Day	35% 4 10% 28% 21% 2	2090
October	1st to 10th	Day	37% 4 9% 29% 21% 1	1943
	11th to 20th	Day	46% 2 10% 24% 17% 2	1900
	21st to end	Day	48% 2 12% 24% 11% 3	1947
November	1st to 10th	Day	37% 3 15% 27% 15% 3	1681
	11th to 20th	Day	52% 2 12% 23% 10% 1	1710
	21st to end	Day	52% 3 14% 22% 8%	1563
December	1st to 10th	Day	55% 2 13% 20% 8% 1	1520
	11th to 20th	Day	58% 3 12% 19% 8% 1	1915
	21st to end	Day	76% 3 8% 8% 5%	2783
January	1st to 10th	Night	59% 1 11% 19% 9%	4428
	11th to 20th	Night	64% 2 11% 13% 10%	4440
	21st to end	Night	67% 2 8% 16% 6% 1	4651
February	1st to 10th	Night	54% 3 9% 19% 13% 1	2470
	11th to 20th	Night	46% 4 10% 25% 14% 1	2257
	21st to end	Night	52% 2 9% 21% 13% 3	1884
March	1st to 10th	Night	48% 2 12% 24% 13% 2	3733
	11th to 20th	Night	38% 2 10% 29% 19% 2	3608
	21st to end	Night	63% 2 11% 18% 6% 1	3530
April	1st to 10th	Night	48% 2 10% 24% 14% 2	1900
	11th to 20th	Night	46% 3 7% 24% 17% 4	1875
	21st to end	Night	48% 4 10% 24% 11% 3	1879
May	1st to 10th	Night	51% 3 10% 20% 14% 3	2782
	11th to 20th	Night	42% 2 16% 28% 12% 1	2507
	21st to end	Night	36% 3 11% 25% 22% 3	2751
June	1st to 10th	Night	33% 4 14% 27% 19% 3	1520
	11th to 20th	Night	33% 4 11% 25% 24% 4	1520
	21st to end	Night	37% 5% 15% 22% 18% 3	1520
July	1st to 10th	Night	43% 4 15% 22% 12% 3	2490
	11th to 20th	Night	26% 6% 12% 32% 22% 2	2482
	21st to end	Night	31% 10% 15% 21% 19% 5%	2662
August	1st to 10th	Night	27% 6% 17% 31% 19% 2	2685
	11th to 20th	Night	30% 6% 15% 31% 17% 1	3095
	21st to end	Night	29% 5% 12% 32% 19% 3	3476
September	1st to 10th	Night	29% 3 10% 27% 27% 4	1900
	11th to 20th	Night	30% 3 9% 31% 23% 3	1942
	21st to end	Night	34% 4 9% 29% 21% 3	2090
October	1st to 10th	Night	34% 3 9% 27% 24% 3	2232
	11th to 20th	Night	41% 3 8% 25% 21% 3	2280
	21st to end	Night	48% 3 9% 25% 14% 2	2650
November	1st to 10th	Night	34% 4 12% 28% 19% 4	2431
	11th to 20th	Night	47% 3 11% 25% 13% 2	2470
	21st to end	Night	48% 3 10% 26% 12% 1	2612
December	1st to 10th	Night	53% 3 12% 23% 9% 1	2660
	11th to 20th	Night	55% 2 11% 23% 9% 1	3281
	21st to end	Night	73% 2 7% 13% 5%	4884

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	20% 10% 36% 25% 8% 1	270
	11th to 20th	Day	20% 13% 43% 17% 6% 1	270
	21st to end	Day	23% 13% 34% 23% 5% 2	297
February	1st to 10th	Day	21% 16% 35% 23% 5%	270
	11th to 20th	Day	23% 17% 31% 23% 6%	270
	21st to end	Day	20% 20% 42% 15% 3	225
March	1st to 10th	Day	23% 20% 33% 18% 6%	270
	11th to 20th	Day	23% 18% 33% 18% 7% 1	270
	21st to end	Day	26% 14% 33% 19% 6% 1	468
April	1st to 10th	Day	27% 15% 30% 22% 5% 1	460
	11th to 20th	Day	20% 20% 28% 21% 9% 2	452
	21st to end	Day	25% 13% 31% 19% 10% 2	460
May	1st to 10th	Day	19% 14% 31% 27% 8% 2	493
	11th to 20th	Day	21% 11% 27% 25% 14% 3	675
	21st to end	Day	14% 9% 28% 23% 16% 9%	734
June	1st to 10th	Day	10% 6% 27% 32% 19% 5%	680
	11th to 20th	Day	10% 5% 29% 34% 16% 5%	680
	21st to end	Day	13% 8% 30% 30% 14% 5%	680
July	1st to 10th	Day	11% 3 15% 30% 24% 16%	671
	11th to 20th	Day	11% 3 21% 32% 23% 10%	668
	21st to end	Day	6% 4 17% 35% 30% 8%	739
August	1st to 10th	Day	6% 3 20% 33% 28% 10%	676
	11th to 20th	Day	10% 6% 17% 29% 23% 15%	502
	21st to end	Day	7% 4 18% 31% 30% 10%	539
September	1st to 10th	Day	14% 5% 19% 31% 23% 7%	490
	11th to 20th	Day	11% 2 19% 32% 25% 12%	490
	21st to end	Day	11% 11% 27% 25% 21% 5%	490
October	1st to 10th	Day	16% 7% 26% 29% 18% 4	343
	11th to 20th	Day	17% 19% 35% 16% 12% 1	300
	21st to end	Day	32% 12% 28% 23% 5%	330
November	1st to 10th	Day	14% 14% 37% 22% 10% 3	273
	11th to 20th	Day	20% 19% 32% 19% 8% 2	270
	21st to end	Day	24% 12% 36% 21% 7%	270
December	1st to 10th	Day	18% 15% 37% 22% 6% 2	270
	11th to 20th	Day	17% 10% 39% 25% 7%	270
	21st to end	Day	24% 19% 37% 17% 3	297
January	1st to 10th	Night	19% 12% 39% 23% 6% 1	950
	11th to 20th	Night	19% 14% 36% 24% 6%	950
	21st to end	Night	22% 11% 35% 28% 4	1045
February	1st to 10th	Night	22% 11% 37% 25% 4	950
	11th to 20th	Night	19% 12% 38% 27% 5%	781
	21st to end	Night	21% 14% 39% 21% 4	628
March	1st to 10th	Night	23% 10% 38% 23% 6% 1	760
	11th to 20th	Night	17% 10% 33% 34% 7%	646
	21st to end	Night	24% 10% 36% 22% 7% 1	627
April	1st to 10th	Night	23% 14% 35% 23% 5%	570
	11th to 20th	Night	22% 13% 33% 25% 6%	563
	21st to end	Night	18% 13% 31% 30% 7% 1	570
May	1st to 10th	Night	18% 9% 34% 31% 7% 1	570
	11th to 20th	Night	19% 5% 30% 35% 11%	561
	21st to end	Night	14% 6% 29% 35% 15% 1	617
June	1st to 10th	Night	9% 4 25% 49% 12% 1	570
	11th to 20th	Night	9% 5% 30% 42% 14% 1	570
	21st to end	Night	11% 4 27% 42% 15%	570
July	1st to 10th	Night	10% 2 13% 42% 29% 5%	555
	11th to 20th	Night	8% 2 19% 41% 26% 3	552
	21st to end	Night	6% 1 17% 46% 29% 2	624
August	1st to 10th	Night	6% 2 15% 42% 31% 4	567
	11th to 20th	Night	8% 2 14% 41% 30% 5%	564
	21st to end	Night	9% 1 15% 42% 30% 2	627
September	1st to 10th	Night	12% 3 18% 38% 27% 4	570
	11th to 20th	Night	10% 4 21% 36% 25% 4	612
	21st to end	Night	11% 8% 27% 35% 18% 2	760
October	1st to 10th	Night	13% 7% 29% 33% 17% 2	760
	11th to 20th	Night	20% 11% 31% 26% 12%	760
	21st to end	Night	25% 11% 32% 25% 8%	836
November	1st to 10th	Night	16% 6% 41% 26% 10% 1	748
	11th to 20th	Night	19% 13% 38% 25% 5%	760
	21st to end	Night	22% 11% 34% 26% 6%	902
December	1st to 10th	Night	22% 12% 37% 24% 5%	950
	11th to 20th	Night	23% 10% 34% 26% 6%	950
	21st to end	Night	27% 14% 34% 23% 2	1045

Page generated at 2024-10-30 12:19:23. Version ac07

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