Waldport
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Waldport clear sky chart from 2005-11-06 to 2026-10-14.

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	20% 10% 3 6% 4 4 4 3 5% 7% 35%	159150
	Night	23% 13% 3 7% 4 3 3 3 4 5% 31%	149993
Transparency	Day	50% 3 12% 19% 12% 4	153917
	Night	57% 4 9% 15% 11% 5%	146228
Seeing	Day	28% 13% 27% 21% 9% 2	17541
	Night	31% 7% 14% 27% 19% 3	26129

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	41% 18% 4 9% 5% 4 3 2 3 3 10%	4722
	11th to 20th	Day	22% 7% 2 5% 3 2 3 2 4 6% 43%	4957
	21st to end	Day	31% 9% 2 7% 4 4 4 3 4 4 28%	5843
February	1st to 10th	Day	34% 13% 4 7% 6% 4 3 3 4 5% 16%	1890
	11th to 20th	Day	32% 13% 3 8% 6% 4 5% 3 4 5% 18%	1845
	21st to end	Day	33% 17% 2 7% 4 3 3 3 4 4 18%	1590
March	1st to 10th	Day	21% 19% 3 8% 5% 5% 6% 4 6% 6% 17%	5047
	11th to 20th	Day	34% 14% 3 7% 4 3 3 2 3 4 22%	5110
	21st to end	Day	31% 16% 4 10% 6% 5% 5% 3 5% 5% 10%	5607
April	1st to 10th	Day	32% 14% 3 7% 5% 4 5% 5% 5% 6% 15%	2506
	11th to 20th	Day	28% 13% 3 8% 5% 4 4 3 5% 6% 23%	2540
	21st to end	Day	28% 10% 3 6% 5% 4 5% 4 6% 6% 24%	2730
May	1st to 10th	Day	17% 11% 4 7% 4 4 4 3 5% 8% 35%	7739
	11th to 20th	Day	15% 11% 3 7% 5% 4 5% 5% 7% 9% 30%	8160
	21st to end	Day	18% 9% 3 6% 4 4 4 4 6% 9% 32%	8992
June	1st to 10th	Day	27% 9% 3 6% 4 4 4 3 5% 7% 30%	2940
	11th to 20th	Day	22% 9% 3 6% 4 4 5% 3 5% 8% 30%	2940
	21st to end	Day	15% 8% 2 6% 4 3 4 3 4 8% 42%	3149
July	1st to 10th	Day	3 6% 2 4 3 3 3 3 5% 8% 60%	8399
	11th to 20th	Day	6% 5% 2 5% 3 3 3 3 4 7% 60%	8220
	21st to end	Day	8% 8% 3 6% 3 3 4 3 5% 8% 50%	8569
August	1st to 10th	Day	6% 7% 2 5% 3 3 3 3 4 8% 55%	7547
	11th to 20th	Day	8% 8% 3 7% 4 5% 5% 4 7% 9% 41%	7563
	21st to end	Day	6% 7% 3 6% 4 4 5% 3 6% 10% 46%	8092
September	1st to 10th	Day	8% 6% 2 5% 3 3 4 3 5% 7% 54%	2520
	11th to 20th	Day	12% 7% 3 7% 3 4 4 3 5% 8% 43%	2427
	21st to end	Day	18% 6% 2 5% 3 3 4 3 5% 7% 44%	2264
October	1st to 10th	Day	17% 6% 2 5% 3 3 3 2 4 5% 50%	3380
	11th to 20th	Day	23% 9% 3 8% 5% 5% 5% 3 5% 7% 28%	3292
	21st to end	Day	31% 9% 3 6% 3 4 4 3 5% 8% 24%	3558
November	1st to 10th	Day	36% 10% 3 7% 3 5% 4 3 5% 5% 19%	1752
	11th to 20th	Day	37% 10% 3 7% 4 3 4 3 5% 6% 19%	1680
	21st to end	Day	31% 11% 3 6% 4 3 4 3 4 6% 23%	1680
December	1st to 10th	Day	25% 7% 3 6% 4 3 3 3 4 5% 38%	2700
	11th to 20th	Day	38% 14% 4 9% 5% 4 4 3 4 4 13%	3108
	21st to end	Day	45% 15% 4 7% 3 3 3 2 3 3 10%	4092
January	1st to 10th	Night	41% 15% 3 8% 5% 4 3 2 4 4 12%	8172
	11th to 20th	Night	22% 10% 2 5% 3 3 2 2 4 4 43%	8009
	21st to end	Night	32% 11% 3 6% 3 3 2 2 3 3 30%	8371
February	1st to 10th	Night	32% 14% 4 8% 6% 4 4 3 5% 4 17%	2730
	11th to 20th	Night	31% 14% 3 8% 4 4 4 2 3 4 22%	2662
	21st to end	Night	34% 13% 3 6% 4 4 3 3 4 4 21%	2215
March	1st to 10th	Night	23% 19% 3 9% 6% 6% 5% 4 4 5% 16%	5063
	11th to 20th	Night	30% 16% 3 8% 4 3 4 2 3 3 24%	5110
	21st to end	Night	35% 17% 4 8% 5% 4 4 3 4 4 12%	5610
April	1st to 10th	Night	30% 14% 3 9% 4 4 4 3 3 5% 19%	2112
	11th to 20th	Night	24% 15% 3 7% 5% 4 4 4 5% 5% 24%	2023
	21st to end	Night	25% 15% 3 6% 4 3 3 3 4 6% 26%	1890
May	1st to 10th	Night	17% 16% 4 8% 4 3 3 2 3 5% 36%	5203
	11th to 20th	Night	21% 14% 4 9% 6% 4 4 3 5% 5% 25%	4700
	21st to end	Night	19% 13% 2 5% 3 3 4 3 5% 7% 35%	5181
June	1st to 10th	Night	21% 9% 3 8% 5% 4 4 3 5% 5% 31%	1680
	11th to 20th	Night	18% 11% 3 6% 5% 3 4 3 5% 8% 34%	1667
	21st to end	Night	16% 13% 4 5% 3 3 3 2 4 6% 40%	1470
July	1st to 10th	Night	4 14% 4 6% 3 2 2 2 3 5% 55%	4534
	11th to 20th	Night	5% 12% 4 8% 4 3 3 2 3 5% 51%	4740
	21st to end	Night	8% 20% 6% 8% 5% 3 2 2 3 5% 38%	5509
August	1st to 10th	Night	7% 14% 5% 10% 4 3 2 2 3 6% 43%	5275
	11th to 20th	Night	11% 21% 5% 9% 4 3 3 2 4 5% 32%	5292
	21st to end	Night	9% 15% 5% 7% 3 3 3 2 4 5% 46%	6138
September	1st to 10th	Night	12% 8% 3 5% 2 3 3 3 4 6% 53%	2100
	11th to 20th	Night	13% 9% 3 7% 4 4 4 3 4 5% 46%	2189
	21st to end	Night	16% 8% 2 5% 3 3 3 3 4 7% 45%	2355
October	1st to 10th	Night	13% 8% 3 7% 3 3 3 2 4 5% 49%	4040
	11th to 20th	Night	21% 10% 4 7% 5% 5% 4 4 5% 7% 29%	3933
	21st to end	Night	32% 9% 3 7% 4 4 4 3 4 5% 25%	4253
November	1st to 10th	Night	32% 10% 2 8% 4 4 4 4 5% 6% 21%	2765
	11th to 20th	Night	39% 8% 3 7% 4 4 4 3 4 5% 20%	2940
	21st to end	Night	27% 10% 3 7% 5% 4 4 3 4 5% 27%	2940
December	1st to 10th	Night	23% 9% 2 5% 4 3 4 3 4 5% 38%	4700
	11th to 20th	Night	42% 13% 4 8% 4 3 3 3 4 4 13%	5316
	21st to end	Night	40% 14% 4 8% 4 3 3 2 3 4 15%	7106

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	82% 2 5% 7% 4 1	4723
	11th to 20th	Day	44% 2 7% 15% 18% 14%	4957
	21st to end	Day	61% 2 6% 10% 13% 7%	5843
February	1st to 10th	Day	71% 3 9% 11% 5% 2	1890
	11th to 20th	Day	70% 3 9% 9% 6% 2	1854
	21st to end	Day	71% 2 8% 10% 7% 2	1590
March	1st to 10th	Day	68% 3 12% 13% 4	5047
	11th to 20th	Day	68% 3 5% 14% 9% 1	5110
	21st to end	Day	77% 3 11% 7% 3	5607
April	1st to 10th	Day	70% 3 12% 12% 4	2506
	11th to 20th	Day	64% 2 10% 15% 7% 2	2543
	21st to end	Day	61% 4 12% 17% 6% 1	2730
May	1st to 10th	Day	49% 2 12% 27% 11%	7739
	11th to 20th	Day	48% 6% 19% 20% 7%	8163
	21st to end	Day	48% 4 24% 21% 2	8994
June	1st to 10th	Day	55% 3 14% 21% 7%	2940
	11th to 20th	Day	51% 4 18% 21% 5% 1	2940
	21st to end	Day	40% 3 18% 25% 11% 3	3149
July	1st to 10th	Day	23% 4 12% 28% 19% 15%	8331
	11th to 20th	Day	23% 5% 7% 18% 38% 11%	8145
	21st to end	Day	30% 6% 12% 31% 18% 3	8378
August	1st to 10th	Day	25% 4 7% 25% 26% 13%	5976
	11th to 20th	Day	37% 6% 16% 30% 10% 1	5962
	21st to end	Day	31% 4 17% 28% 15% 4	6347
September	1st to 10th	Day	30% 2 10% 30% 17% 10%	2520
	11th to 20th	Day	39% 4 14% 22% 16% 5%	2427
	21st to end	Day	41% 3 12% 23% 17% 4	2264
October	1st to 10th	Day	38% 2 6% 23% 26% 5%	3380
	11th to 20th	Day	56% 4 14% 15% 10% 1	3292
	21st to end	Day	59% 4 9% 17% 10% 2	3558
November	1st to 10th	Day	68% 3 7% 16% 5% 1	1752
	11th to 20th	Day	68% 3 9% 10% 7% 4	1680
	21st to end	Day	63% 3 8% 12% 8% 6%	1680
December	1st to 10th	Day	51% 2 9% 13% 21% 4	2700
	11th to 20th	Day	77% 2 10% 7% 4	3108
	21st to end	Day	81% 1 7% 7% 2 1	4092
January	1st to 10th	Night	79% 2 7% 7% 3 2	8172
	11th to 20th	Night	47% 2 6% 14% 17% 14%	8009
	21st to end	Night	61% 2 4 7% 16% 10%	8371
February	1st to 10th	Night	72% 3 8% 10% 5% 2	2730
	11th to 20th	Night	68% 3 8% 13% 7% 3	2664
	21st to end	Night	68% 3 8% 12% 8% 2	2215
March	1st to 10th	Night	72% 3 7% 14% 4	5063
	11th to 20th	Night	68% 3 8% 11% 9% 1	5110
	21st to end	Night	76% 3 9% 10% 2	5610
April	1st to 10th	Night	70% 2 10% 13% 4 1	2112
	11th to 20th	Night	62% 4 10% 16% 6% 3	2023
	21st to end	Night	60% 3 11% 18% 6% 2	1890
May	1st to 10th	Night	51% 3 10% 26% 9% 1	5201
	11th to 20th	Night	59% 3 11% 20% 6% 2	4700
	21st to end	Night	49% 3 26% 19% 3	5182
June	1st to 10th	Night	53% 4 15% 23% 5%	1680
	11th to 20th	Night	47% 5% 15% 25% 7% 1	1667
	21st to end	Night	45% 3 14% 27% 8% 4	1470
July	1st to 10th	Night	31% 6% 9% 20% 18% 17%	4494
	11th to 20th	Night	31% 7% 7% 13% 28% 13%	4692
	21st to end	Night	45% 7% 9% 19% 16% 4	5389
August	1st to 10th	Night	35% 8% 7% 18% 17% 15%	4169
	11th to 20th	Night	53% 6% 9% 21% 9% 2	4169
	21st to end	Night	36% 4 13% 27% 16% 4	4809
September	1st to 10th	Night	33% 3 10% 25% 18% 10%	2100
	11th to 20th	Night	41% 3 12% 23% 15% 7%	2189
	21st to end	Night	39% 3 13% 21% 15% 8%	2355
October	1st to 10th	Night	38% 4 6% 25% 22% 5%	4040
	11th to 20th	Night	52% 5% 15% 15% 11% 2	3933
	21st to end	Night	61% 3 8% 17% 7% 3	4253
November	1st to 10th	Night	65% 4 9% 13% 8% 1	2765
	11th to 20th	Night	68% 3 9% 10% 7% 4	2940
	21st to end	Night	59% 4 8% 13% 10% 7%	2940
December	1st to 10th	Night	48% 3 7% 15% 21% 5%	4700
	11th to 20th	Night	76% 3 7% 7% 5% 1	5316
	21st to end	Night	77% 2 9% 9% 3 1	7106

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	50% 14% 22% 8% 5%	220
	11th to 20th	Day	41% 8% 20% 20% 11% 1	294
	21st to end	Day	40% 9% 19% 21% 9% 2	473
February	1st to 10th	Day	43% 12% 20% 20% 5%	430
	11th to 20th	Day	44% 14% 22% 16% 3 1	425
	21st to end	Day	47% 14% 19% 16% 3 1	374
March	1st to 10th	Day	42% 14% 21% 18% 5%	540
	11th to 20th	Day	43% 12% 20% 17% 6% 2	540
	21st to end	Day	43% 16% 20% 15% 5% 1	594
April	1st to 10th	Day	39% 13% 22% 18% 6% 1	540
	11th to 20th	Day	36% 17% 25% 13% 6% 2	532
	21st to end	Day	32% 18% 26% 16% 6% 2	540
May	1st to 10th	Day	29% 14% 31% 16% 7% 3	543
	11th to 20th	Day	34% 17% 24% 16% 6% 2	568
	21st to end	Day	27% 13% 29% 19% 8% 3	617
June	1st to 10th	Day	28% 14% 28% 18% 8% 3	570
	11th to 20th	Day	24% 19% 33% 16% 7% 2	570
	21st to end	Day	14% 12% 39% 25% 8% 2	779
July	1st to 10th	Day	9% 12% 41% 25% 10% 2	629
	11th to 20th	Day	10% 13% 37% 27% 11% 4	564
	21st to end	Day	5% 10% 37% 32% 12% 4	619
August	1st to 10th	Day	8% 8% 36% 29% 14% 4	567
	11th to 20th	Day	9% 6% 35% 32% 14% 5%	557
	21st to end	Day	9% 11% 34% 29% 11% 6%	627
September	1st to 10th	Day	10% 12% 31% 27% 15% 6%	570
	11th to 20th	Day	16% 13% 27% 26% 12% 4	570
	21st to end	Day	19% 12% 27% 25% 14% 3	570
October	1st to 10th	Day	21% 13% 25% 24% 14% 4	570
	11th to 20th	Day	27% 13% 21% 20% 16% 3	543
	21st to end	Day	36% 11% 23% 18% 9% 3	583
November	1st to 10th	Day	40% 12% 21% 17% 10% 1	301
	11th to 20th	Day	41% 11% 23% 15% 9% 1	220
	21st to end	Day	40% 9% 19% 25% 8%	220
December	1st to 10th	Day	44% 7% 22% 11% 13% 3	220
	11th to 20th	Day	52% 12% 22% 9% 4	220
	21st to end	Day	51% 10% 19% 16% 5%	242
January	1st to 10th	Night	50% 9% 15% 16% 9% 1	840
	11th to 20th	Night	41% 6% 15% 21% 13% 3	840
	21st to end	Night	37% 7% 13% 27% 14% 2	924
February	1st to 10th	Night	40% 7% 13% 28% 11% 2	840
	11th to 20th	Night	39% 10% 13% 25% 13% 1	824
	21st to end	Night	43% 10% 13% 23% 12%	692
March	1st to 10th	Night	42% 7% 15% 23% 12% 1	840
	11th to 20th	Night	39% 8% 13% 26% 13% 2	840
	21st to end	Night	44% 9% 12% 22% 12% 1	924
April	1st to 10th	Night	38% 9% 11% 25% 15% 2	840
	11th to 20th	Night	32% 9% 17% 25% 14% 3	775
	21st to end	Night	34% 7% 11% 29% 17% 2	630
May	1st to 10th	Night	27% 7% 14% 29% 20% 3	588
	11th to 20th	Night	31% 7% 12% 26% 22% 2	414
	21st to end	Night	29% 6% 17% 24% 21% 3	455
June	1st to 10th	Night	25% 6% 17% 30% 19% 2	420
	11th to 20th	Night	21% 7% 19% 35% 17% 2	420
	21st to end	Night	21% 4 15% 31% 26% 2	420
July	1st to 10th	Night	12% 5% 14% 36% 30% 3	410
	11th to 20th	Night	14% 3 21% 35% 25% 2	408
	21st to end	Night	10% 3 16% 34% 31% 6%	585
August	1st to 10th	Night	13% 4 10% 34% 33% 7%	627
	11th to 20th	Night	12% 4 8% 28% 39% 8%	624
	21st to end	Night	14% 4 14% 33% 31% 5%	793
September	1st to 10th	Night	14% 4 15% 28% 34% 5%	840
	11th to 20th	Night	16% 5% 11% 29% 28% 11%	840
	21st to end	Night	20% 5% 11% 32% 28% 5%	840
October	1st to 10th	Night	20% 5% 13% 30% 27% 5%	840
	11th to 20th	Night	25% 4 13% 29% 22% 7%	812
	21st to end	Night	33% 8% 16% 23% 16% 4	880
November	1st to 10th	Night	39% 7% 12% 27% 15% 1	820
	11th to 20th	Night	44% 8% 12% 23% 12% 1	840
	21st to end	Night	31% 8% 16% 29% 13% 3	840
December	1st to 10th	Night	37% 5% 17% 23% 17% 2	840
	11th to 20th	Night	46% 8% 14% 21% 10% 1	840
	21st to end	Night	48% 10% 14% 20% 6% 1	924

Page generated at 2026-10-11 02:06:31. Version ac07

Copyright © 2026 Attilla Danko.