Katepwa Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Katepwa Lake clear sky chart from 2005-11-06 to 2024-11-05.

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% 8% 3 8% 5% 5% 5% 4 6% 8% 38%	105811
	Night	8% 9% 3 9% 6% 5% 5% 4 6% 7% 38%	101794
Transparency	Day	44% 6% 16% 26% 9% 1	105566
	Night	44% 5% 15% 24% 10% 1	101685
Seeing	Day	13% 8% 28% 29% 16% 4	16154
	Night	13% 7% 29% 35% 14% 2	25602

By Month

Percentage Cloud Cover NW (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	6% 15% 6% 15% 8% 8% 6% 4 8% 7% 16%	2233
	11th to 20th	Day	5% 9% 4 13% 11% 11% 9% 8% 8% 8% 14%	2516
	21st to end	Day	6% 13% 6% 12% 8% 6% 6% 3 4 6% 31%	2794
February	1st to 10th	Day	7% 14% 5% 15% 7% 6% 8% 6% 6% 6% 20%	1520
	11th to 20th	Day	7% 10% 6% 11% 8% 7% 8% 6% 6% 6% 25%	1659
	21st to end	Day	6% 9% 5% 11% 10% 8% 7% 5% 8% 8% 23%	1570
March	1st to 10th	Day	8% 13% 5% 14% 8% 6% 6% 4 5% 7% 24%	3130
	11th to 20th	Day	6% 11% 5% 15% 7% 6% 4 3 5% 7% 30%	3250
	21st to end	Day	8% 9% 4 12% 6% 5% 5% 4 6% 8% 33%	4165
April	1st to 10th	Day	7% 9% 3 8% 6% 5% 6% 5% 7% 8% 36%	2280
	11th to 20th	Day	15% 16% 4 9% 5% 5% 3 4 4 7% 29%	2321
	21st to end	Day	14% 8% 2 8% 4 5% 5% 4 6% 8% 36%	2579
May	1st to 10th	Day	19% 10% 3 5% 4 3 3 3 5% 7% 37%	4430
	11th to 20th	Day	12% 7% 3 7% 5% 5% 6% 4 7% 9% 35%	4388
	21st to end	Day	14% 7% 2 7% 5% 5% 5% 5% 7% 8% 35%	5102
June	1st to 10th	Day	16% 6% 2 7% 5% 4 6% 4 7% 7% 36%	2877
	11th to 20th	Day	18% 7% 3 7% 5% 6% 6% 4 7% 7% 30%	3040
	21st to end	Day	12% 5% 2 6% 5% 4 6% 5% 7% 8% 40%	3040
July	1st to 10th	Day	6% 4 2 5% 5% 6% 6% 5% 8% 11% 44%	5060
	11th to 20th	Day	6% 3 1 5% 3 4 5% 4 7% 9% 52%	4507
	21st to end	Day	5% 3 2 4 3 4 4 3 6% 9% 56%	4802
August	1st to 10th	Day	8% 5% 2 6% 5% 4 5% 4 7% 8% 46%	4412
	11th to 20th	Day	6% 4 2 5% 4 5% 6% 4 7% 11% 48%	4343
	21st to end	Day	12% 5% 2 5% 3 4 4 3 5% 7% 50%	4296
September	1st to 10th	Day	12% 5% 2 5% 3 4 4 3 5% 8% 49%	2280
	11th to 20th	Day	12% 8% 3 6% 4 4 3 3 6% 8% 42%	2232
	21st to end	Day	13% 7% 2 4 4 2 4 3 4 7% 49%	2090
October	1st to 10th	Day	11% 9% 3 6% 4 4 5% 3 6% 7% 43%	3206
	11th to 20th	Day	7% 7% 3 5% 3 3 4 3 6% 11% 49%	2939
	21st to end	Day	8% 10% 5% 9% 4 4 4 4 6% 7% 38%	3091
November	1st to 10th	Day	15% 15% 4 9% 8% 5% 4 3 4 5% 27%	1634
	11th to 20th	Day	7% 15% 5% 14% 9% 5% 4 4 6% 6% 26%	1468
	21st to end	Day	10% 16% 6% 11% 6% 6% 4 4 5% 5% 28%	1330
December	1st to 10th	Day	7% 14% 5% 12% 11% 7% 7% 5% 6% 4 21%	1330
	11th to 20th	Day	8% 17% 7% 17% 8% 5% 7% 4 6% 5% 16%	1679
	21st to end	Day	5% 9% 3 7% 5% 5% 4 4 4 5% 49%	2218
January	1st to 10th	Night	5% 15% 6% 14% 8% 6% 6% 4 6% 7% 24%	4693
	11th to 20th	Night	5% 8% 4 16% 12% 11% 9% 5% 6% 6% 18%	4392
	21st to end	Night	6% 12% 4 12% 8% 5% 5% 5% 7% 6% 31%	4873
February	1st to 10th	Night	8% 11% 5% 11% 7% 7% 7% 5% 7% 8% 24%	2660
	11th to 20th	Night	4 11% 5% 12% 8% 7% 7% 5% 7% 7% 28%	2424
	21st to end	Night	4 10% 4 11% 8% 7% 7% 4 7% 8% 31%	1884
March	1st to 10th	Night	7% 12% 6% 12% 7% 5% 5% 4 5% 9% 29%	3734
	11th to 20th	Night	5% 12% 4 8% 6% 5% 5% 5% 5% 8% 36%	3706
	21st to end	Night	6% 9% 4 12% 7% 6% 5% 4 7% 8% 32%	3477
April	1st to 10th	Night	6% 9% 3 5% 5% 5% 4 4 7% 8% 44%	1900
	11th to 20th	Night	14% 11% 3 8% 5% 4 5% 4 6% 7% 33%	1809
	21st to end	Night	15% 7% 3 7% 6% 5% 5% 5% 6% 6% 36%	1599
May	1st to 10th	Night	19% 9% 3 7% 4 4 5% 4 4 5% 36%	2540
	11th to 20th	Night	11% 6% 3 7% 4 5% 5% 5% 6% 8% 41%	2518
	21st to end	Night	15% 5% 1 6% 4 4 5% 4 6% 8% 42%	2482
June	1st to 10th	Night	12% 6% 2 5% 5% 4 3 5% 6% 7% 46%	1300
	11th to 20th	Night	17% 7% 2 5% 4 5% 5% 5% 5% 6% 38%	1140
	21st to end	Night	12% 6% 2 5% 4 3 5% 3 7% 7% 47%	1140
July	1st to 10th	Night	7% 3 1 5% 4 4 5% 5% 8% 11% 47%	1900
	11th to 20th	Night	6% 3 2 4 3 4 4 4 6% 8% 57%	2456
	21st to end	Night	3 3 1 3 2 2 3 4 5% 8% 65%	2762
August	1st to 10th	Night	7% 5% 2 4 3 4 4 4 6% 8% 54%	2528
	11th to 20th	Night	6% 3 1 5% 3 5% 5% 4 7% 10% 51%	2496
	21st to end	Night	7% 4 2 4 4 3 4 4 6% 9% 53%	3368
September	1st to 10th	Night	9% 5% 2 6% 3 4 4 3 5% 6% 52%	1900
	11th to 20th	Night	12% 6% 2 5% 3 4 5% 4 6% 8% 46%	1948
	21st to end	Night	11% 6% 2 5% 4 3 4 4 6% 6% 49%	2090
October	1st to 10th	Night	11% 8% 2 6% 3 4 4 3 5% 7% 47%	3760
	11th to 20th	Night	6% 6% 2 5% 3 4 5% 4 7% 10% 46%	3957
	21st to end	Night	8% 10% 4 8% 4 3 4 3 6% 8% 43%	4467
November	1st to 10th	Night	15% 14% 4 9% 6% 4 4 3 4 5% 30%	2541
	11th to 20th	Night	8% 14% 5% 12% 8% 5% 5% 4 5% 5% 28%	2712
	21st to end	Night	9% 13% 5% 11% 7% 5% 4 4 6% 6% 31%	2850
December	1st to 10th	Night	6% 12% 6% 13% 8% 7% 6% 6% 6% 5% 25%	2850
	11th to 20th	Night	8% 14% 6% 15% 7% 7% 6% 4 6% 6% 21%	3518
	21st to end	Night	5% 7% 3 9% 6% 5% 4 4 5% 7% 44%	5420

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	65% 6% 14% 11% 4	2233
	11th to 20th	Day	63% 6% 14% 13% 4	2540
	21st to end	Day	55% 4 11% 24% 5%	2794
February	1st to 10th	Day	62% 6% 13% 13% 6%	1520
	11th to 20th	Day	56% 5% 10% 17% 11%	1668
	21st to end	Day	56% 7% 13% 16% 9%	1570
March	1st to 10th	Day	58% 6% 14% 18% 4	3130
	11th to 20th	Day	54% 6% 17% 18% 5%	3251
	21st to end	Day	47% 6% 14% 19% 13% 1	4165
April	1st to 10th	Day	42% 7% 16% 25% 10%	2280
	11th to 20th	Day	56% 5% 12% 17% 8% 2	2321
	21st to end	Day	45% 5% 18% 24% 8% 1	2579
May	1st to 10th	Day	45% 5% 15% 25% 9%	4430
	11th to 20th	Day	43% 7% 12% 23% 14% 1	4392
	21st to end	Day	42% 9% 13% 28% 8%	5102
June	1st to 10th	Day	43% 6% 15% 25% 9% 1	2877
	11th to 20th	Day	51% 7% 15% 18% 9% 1	3040
	21st to end	Day	38% 8% 19% 25% 9%	3040
July	1st to 10th	Day	33% 7% 26% 29% 6%	4981
	11th to 20th	Day	27% 6% 18% 40% 9%	4428
	21st to end	Day	24% 5% 17% 38% 14% 1	4651
August	1st to 10th	Day	34% 6% 18% 28% 12% 1	4396
	11th to 20th	Day	30% 5% 22% 37% 5%	4385
	21st to end	Day	33% 5% 15% 37% 9%	4295
September	1st to 10th	Day	35% 4 14% 32% 13% 2	2280
	11th to 20th	Day	40% 5% 16% 26% 12% 1	2232
	21st to end	Day	35% 4 15% 32% 12% 2	2090
October	1st to 10th	Day	40% 4 18% 29% 8% 1	3206
	11th to 20th	Day	32% 2 18% 38% 9% 1	2939
	21st to end	Day	45% 4 18% 26% 7%	3091
November	1st to 10th	Day	60% 4 14% 14% 7%	1634
	11th to 20th	Day	59% 6% 14% 14% 7% 1	1468
	21st to end	Day	59% 5% 15% 16% 5%	1330
December	1st to 10th	Day	63% 5% 11% 14% 6%	1330
	11th to 20th	Day	67% 5% 14% 11% 3	1680
	21st to end	Day	38% 5% 11% 26% 13% 6%	2218
January	1st to 10th	Night	59% 5% 15% 16% 5%	4693
	11th to 20th	Night	65% 5% 14% 12% 4	4430
	21st to end	Night	52% 6% 17% 20% 5%	4873
February	1st to 10th	Night	56% 6% 12% 18% 7% 1	2660
	11th to 20th	Night	52% 6% 13% 19% 10% 1	2425
	21st to end	Night	50% 5% 12% 24% 8%	1884
March	1st to 10th	Night	52% 5% 19% 19% 5%	3734
	11th to 20th	Night	45% 7% 20% 21% 6%	3706
	21st to end	Night	48% 5% 13% 23% 12%	3477
April	1st to 10th	Night	37% 5% 15% 26% 17% 1	1900
	11th to 20th	Night	50% 5% 10% 22% 12% 2	1809
	21st to end	Night	46% 5% 13% 22% 13% 1	1599
May	1st to 10th	Night	48% 4 13% 23% 11% 1	2540
	11th to 20th	Night	40% 7% 13% 22% 16% 3	2518
	21st to end	Night	36% 8% 14% 30% 10% 1	2482
June	1st to 10th	Night	36% 7% 14% 27% 13% 2	1300
	11th to 20th	Night	45% 6% 14% 21% 13% 1	1140
	21st to end	Night	36% 6% 18% 31% 9% 1	1140
July	1st to 10th	Night	30% 7% 30% 26% 7%	1870
	11th to 20th	Night	24% 5% 16% 42% 12% 1	2412
	21st to end	Night	17% 4 22% 35% 17% 4	2674
August	1st to 10th	Night	27% 5% 22% 31% 14% 1	2520
	11th to 20th	Night	27% 5% 20% 38% 9% 1	2520
	21st to end	Night	28% 4 18% 38% 11% 1	3368
September	1st to 10th	Night	33% 5% 12% 30% 18% 2	1900
	11th to 20th	Night	36% 6% 16% 28% 13% 1	1948
	21st to end	Night	35% 4 14% 30% 15% 2	2090
October	1st to 10th	Night	37% 4 16% 32% 9% 3	3760
	11th to 20th	Night	33% 4 15% 35% 11% 1	3957
	21st to end	Night	40% 4 14% 32% 10%	4467
November	1st to 10th	Night	57% 4 12% 17% 8% 1	2541
	11th to 20th	Night	57% 5% 17% 15% 6%	2712
	21st to end	Night	54% 6% 17% 18% 4	2850
December	1st to 10th	Night	59% 6% 13% 16% 5% 1	2850
	11th to 20th	Night	63% 6% 12% 14% 5%	3516
	21st to end	Night	39% 6% 11% 23% 17% 5%	5420

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	13% 10% 29% 30% 13% 5%	228
	11th to 20th	Day	10% 6% 33% 34% 16% 1	270
	21st to end	Day	16% 7% 30% 28% 17% 1	297
February	1st to 10th	Day	14% 11% 28% 32% 14% 1	270
	11th to 20th	Day	10% 8% 31% 32% 15% 4	270
	21st to end	Day	9% 4 24% 41% 17% 5%	225
March	1st to 10th	Day	13% 6% 34% 30% 14% 3	270
	11th to 20th	Day	12% 10% 27% 30% 18% 4	308
	21st to end	Day	16% 9% 31% 27% 14% 3	506
April	1st to 10th	Day	10% 12% 38% 29% 9% 2	460
	11th to 20th	Day	21% 13% 29% 25% 10% 2	519
	21st to end	Day	15% 9% 28% 32% 16%	650
May	1st to 10th	Day	15% 8% 28% 30% 16% 3	653
	11th to 20th	Day	14% 7% 28% 26% 17% 7%	675
	21st to end	Day	16% 5% 27% 27% 17% 7%	734
June	1st to 10th	Day	15% 13% 27% 25% 16% 5%	680
	11th to 20th	Day	19% 13% 29% 25% 12% 4	680
	21st to end	Day	13% 9% 23% 30% 19% 6%	680
July	1st to 10th	Day	7% 5% 23% 33% 24% 7%	671
	11th to 20th	Day	8% 6% 28% 30% 21% 7%	668
	21st to end	Day	7% 6% 27% 32% 19% 9%	739
August	1st to 10th	Day	10% 6% 21% 36% 21% 6%	676
	11th to 20th	Day	8% 5% 21% 34% 24% 8%	665
	21st to end	Day	13% 6% 21% 35% 18% 5%	602
September	1st to 10th	Day	13% 9% 34% 24% 15% 4	490
	11th to 20th	Day	19% 8% 29% 26% 14% 4	442
	21st to end	Day	15% 11% 31% 28% 13% 3	300
October	1st to 10th	Day	21% 11% 25% 20% 20% 3	300
	11th to 20th	Day	17% 10% 31% 25% 12% 4	300
	21st to end	Day	15% 12% 33% 27% 10% 3	330
November	1st to 10th	Day	22% 8% 29% 26% 11% 4	282
	11th to 20th	Day	15% 10% 37% 29% 9%	270
	21st to end	Day	16% 9% 35% 31% 9% 1	270
December	1st to 10th	Day	12% 5% 33% 31% 14% 4	270
	11th to 20th	Day	14% 8% 45% 26% 6% 3	270
	21st to end	Day	13% 5% 32% 30% 16% 4	234
January	1st to 10th	Night	10% 10% 31% 34% 13% 1	950
	11th to 20th	Night	15% 11% 31% 33% 9% 1	950
	21st to end	Night	13% 11% 33% 33% 10% 1	1045
February	1st to 10th	Night	14% 7% 30% 32% 15% 2	950
	11th to 20th	Night	9% 7% 32% 38% 12% 3	768
	21st to end	Night	6% 5% 24% 41% 20% 4	628
March	1st to 10th	Night	13% 7% 29% 36% 14% 2	760
	11th to 20th	Night	10% 6% 32% 36% 16% 1	755
	21st to end	Night	14% 5% 28% 36% 16% 2	627
April	1st to 10th	Night	11% 8% 32% 35% 14% 1	570
	11th to 20th	Night	20% 8% 29% 34% 9% 1	563
	21st to end	Night	18% 6% 32% 34% 10% 1	570
May	1st to 10th	Night	14% 6% 29% 35% 15% 1	570
	11th to 20th	Night	16% 5% 27% 34% 16% 1	561
	21st to end	Night	20% 5% 24% 32% 17% 2	617
June	1st to 10th	Night	16% 5% 27% 36% 15% 2	540
	11th to 20th	Night	20% 7% 26% 34% 12% 1	380
	21st to end	Night	14% 4 24% 38% 18% 1	380
July	1st to 10th	Night	9% 2 23% 40% 23% 2	370
	11th to 20th	Night	9% 3 25% 40% 21% 1	521
	21st to end	Night	6% 4 22% 42% 22% 4	624
August	1st to 10th	Night	8% 3 23% 43% 21% 3	567
	11th to 20th	Night	9% 2 16% 45% 27% 2	564
	21st to end	Night	9% 5% 25% 40% 20% 1	627
September	1st to 10th	Night	11% 5% 26% 36% 20% 2	570
	11th to 20th	Night	14% 6% 23% 42% 14% 1	570
	21st to end	Night	12% 6% 29% 38% 13% 1	570
October	1st to 10th	Night	20% 7% 21% 35% 16% 1	733
	11th to 20th	Night	14% 8% 29% 36% 13% 1	862
	21st to end	Night	16% 10% 31% 34% 8% 1	1045
November	1st to 10th	Night	20% 10% 29% 31% 9% 1	950
	11th to 20th	Night	15% 10% 35% 28% 10% 2	950
	21st to end	Night	14% 10% 36% 33% 6% 1	950
December	1st to 10th	Night	12% 7% 34% 31% 13% 3	950
	11th to 20th	Night	12% 11% 33% 32% 11% 2	950
	21st to end	Night	12% 6% 30% 34% 15% 3	1045

Page generated at 2024-11-03 00:11:28. Version ac07

Copyright © 2024 Attilla Danko.