Waiparous Valley Viewpoint
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Waiparous Valley Viewpoint 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	8% 9% 3 8% 5% 5% 5% 4 6% 8% 37%	105647
	Night	5% 9% 3 8% 5% 5% 5% 4 7% 8% 41%	101973
Transparency	Day	42% 9% 15% 21% 11% 2	105397
	Night	38% 8% 17% 23% 11% 2	101869
Seeing	Day	16% 17% 32% 23% 9% 2	15314
	Night	11% 14% 36% 27% 11% 1	24297

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	1 5% 4 14% 8% 5% 6% 4 8% 9% 38%	2219
	11th to 20th	Day	1 7% 4 9% 7% 5% 6% 6% 8% 9% 39%	2299
	21st to end	Day	1 6% 3 9% 5% 5% 6% 5% 8% 9% 42%	2794
February	1st to 10th	Day	1 6% 3 10% 7% 8% 7% 6% 7% 8% 36%	1520
	11th to 20th	Day	1 7% 5% 12% 6% 6% 7% 6% 8% 9% 34%	1604
	21st to end	Day	1 8% 6% 15% 8% 5% 6% 4 7% 8% 32%	1565
March	1st to 10th	Day	1 6% 4 11% 8% 5% 5% 5% 7% 12% 37%	3138
	11th to 20th	Day	3 10% 4 7% 4 3 4 4 6% 9% 45%	3389
	21st to end	Day	2 16% 9% 21% 6% 4 4 3 5% 6% 24%	3967
April	1st to 10th	Day	5% 16% 5% 11% 6% 6% 5% 4 7% 8% 28%	2299
	11th to 20th	Day	7% 18% 7% 11% 5% 4 4 3 5% 8% 27%	2440
	21st to end	Day	9% 18% 5% 9% 5% 5% 4 4 5% 6% 30%	2470
May	1st to 10th	Day	13% 21% 5% 9% 5% 4 4 4 5% 5% 26%	4376
	11th to 20th	Day	9% 13% 4 9% 5% 4 6% 5% 7% 9% 30%	4694
	21st to end	Day	18% 13% 3 10% 6% 5% 5% 4 6% 6% 24%	5161
June	1st to 10th	Day	19% 11% 3 8% 6% 4 5% 5% 6% 7% 25%	2850
	11th to 20th	Day	24% 12% 3 8% 6% 5% 6% 4 5% 7% 21%	2850
	21st to end	Day	12% 7% 3 8% 6% 6% 6% 4 7% 8% 33%	2850
July	1st to 10th	Day	9% 6% 2 7% 5% 6% 6% 5% 6% 7% 40%	4740
	11th to 20th	Day	8% 4 2 5% 5% 6% 7% 6% 8% 8% 42%	4740
	21st to end	Day	6% 6% 2 5% 5% 5% 5% 4 7% 8% 48%	4956
August	1st to 10th	Day	12% 6% 3 7% 5% 5% 5% 5% 7% 7% 38%	4401
	11th to 20th	Day	11% 5% 2 7% 6% 5% 6% 5% 8% 8% 37%	4150
	21st to end	Day	9% 7% 2 6% 4 4 5% 3 6% 8% 46%	4521
September	1st to 10th	Day	12% 7% 2 7% 3 4 4 4 5% 6% 44%	2325
	11th to 20th	Day	13% 9% 2 6% 4 4 4 3 5% 6% 44%	2114
	21st to end	Day	9% 8% 3 4 4 5% 6% 4 8% 8% 42%	2090
October	1st to 10th	Day	6% 8% 2 7% 4 4 4 4 6% 8% 46%	3386
	11th to 20th	Day	5% 9% 3 6% 5% 4 5% 4 6% 9% 44%	2842
	21st to end	Day	3 9% 4 6% 5% 6% 5% 4 5% 7% 47%	3101
November	1st to 10th	Day	3 11% 5% 8% 6% 6% 6% 5% 6% 7% 36%	1625
	11th to 20th	Day	2 9% 4 6% 5% 5% 5% 5% 6% 8% 46%	1387
	21st to end	Day	2 9% 4 11% 6% 5% 5% 4 6% 9% 41%	1330
December	1st to 10th	Day	2 7% 3 10% 6% 6% 5% 5% 6% 10% 38%	1330
	11th to 20th	Day	2 10% 4 10% 6% 6% 6% 5% 7% 9% 35%	1682
	21st to end	Day	1 8% 4 9% 6% 4 5% 4 6% 7% 45%	2442
January	1st to 10th	Night	1 7% 5% 13% 7% 7% 7% 6% 8% 10% 30%	4726
	11th to 20th	Night	1 7% 3 10% 7% 6% 6% 4 9% 9% 37%	4631
	21st to end	Night	2 9% 5% 9% 6% 6% 5% 4 7% 9% 38%	4862
February	1st to 10th	Night	2 8% 3 11% 7% 5% 6% 5% 8% 9% 37%	2660
	11th to 20th	Night	1 9% 4 11% 7% 6% 7% 5% 7% 9% 34%	2463
	21st to end	Night	1 7% 4 12% 7% 8% 6% 5% 6% 8% 37%	1885
March	1st to 10th	Night	1 6% 3 10% 9% 7% 7% 6% 8% 10% 33%	3736
	11th to 20th	Night	2 8% 3 5% 4 3 4 3 7% 11% 49%	3589
	21st to end	Night	3 16% 7% 16% 6% 4 4 3 5% 7% 29%	3684
April	1st to 10th	Night	5% 13% 5% 10% 7% 5% 4 5% 6% 7% 34%	1880
	11th to 20th	Night	6% 13% 7% 11% 6% 5% 4 4 6% 6% 32%	1691
	21st to end	Night	8% 15% 4 9% 4 4 5% 4 6% 7% 34%	1710
May	1st to 10th	Night	12% 21% 4 8% 4 4 4 3 4 5% 30%	2570
	11th to 20th	Night	8% 11% 4 8% 6% 5% 5% 4 6% 9% 34%	2199
	21st to end	Night	14% 10% 3 8% 5% 5% 5% 3 7% 9% 32%	2414
June	1st to 10th	Night	18% 10% 3 6% 4 3 5% 4 6% 7% 34%	1330
	11th to 20th	Night	21% 9% 3 6% 5% 5% 5% 3 6% 6% 30%	1330
	21st to end	Night	10% 5% 2 6% 5% 5% 4 5% 7% 8% 43%	1330
July	1st to 10th	Night	8% 7% 2 6% 4 4 5% 4 5% 7% 49%	2220
	11th to 20th	Night	7% 3 1 3 3 3 4 4 6% 8% 57%	2220
	21st to end	Night	5% 5% 2 5% 3 3 3 3 4 7% 60%	2593
August	1st to 10th	Night	13% 6% 2 5% 4 4 4 3 7% 10% 43%	2529
	11th to 20th	Night	9% 6% 2 5% 4 4 4 4 7% 11% 45%	2683
	21st to end	Night	9% 5% 2 4 4 3 4 3 5% 8% 53%	3146
September	1st to 10th	Night	10% 8% 2 4 3 3 4 3 5% 6% 51%	1852
	11th to 20th	Night	12% 10% 3 6% 4 3 4 3 5% 7% 45%	2066
	21st to end	Night	7% 9% 2 5% 4 4 4 3 5% 7% 49%	2090
October	1st to 10th	Night	5% 8% 2 5% 4 3 4 3 6% 7% 51%	3590
	11th to 20th	Night	4 7% 2 5% 3 4 5% 4 7% 9% 50%	4086
	21st to end	Night	3 10% 3 7% 4 4 5% 4 6% 8% 48%	4457
November	1st to 10th	Night	3 11% 4 9% 5% 5% 5% 6% 7% 8% 37%	2535
	11th to 20th	Night	2 8% 2 7% 5% 5% 5% 4 7% 10% 45%	2792
	21st to end	Night	2 8% 4 9% 7% 4 4 5% 7% 10% 40%	2850
December	1st to 10th	Night	1 8% 4 10% 5% 6% 5% 5% 7% 9% 39%	2850
	11th to 20th	Night	1 8% 4 10% 7% 6% 6% 6% 8% 9% 35%	3510
	21st to end	Night	1 8% 4 10% 5% 5% 5% 4 7% 8% 42%	5214

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	40% 7% 16% 23% 12% 2	2219
	11th to 20th	Day	39% 8% 11% 18% 19% 5%	2320
	21st to end	Day	31% 11% 19% 29% 8% 1	2794
February	1st to 10th	Day	42% 11% 14% 20% 10% 3	1520
	11th to 20th	Day	42% 11% 15% 20% 11% 2	1613
	21st to end	Day	48% 8% 14% 17% 12% 1	1565
March	1st to 10th	Day	39% 10% 17% 17% 16% 1	3138
	11th to 20th	Day	33% 8% 23% 22% 12% 1	3390
	21st to end	Day	57% 11% 13% 12% 7% 1	3967
April	1st to 10th	Day	53% 9% 17% 14% 7%	2299
	11th to 20th	Day	54% 9% 12% 15% 8% 1	2440
	21st to end	Day	54% 8% 15% 16% 6% 1	2470
May	1st to 10th	Day	57% 8% 12% 20% 3	4376
	11th to 20th	Day	45% 11% 16% 21% 7%	4698
	21st to end	Day	58% 9% 14% 11% 8%	5162
June	1st to 10th	Day	55% 9% 14% 14% 7% 1	2850
	11th to 20th	Day	61% 8% 13% 11% 7% 1	2850
	21st to end	Day	44% 10% 16% 19% 9% 1	2850
July	1st to 10th	Day	37% 9% 12% 17% 19% 6%	4666
	11th to 20th	Day	34% 10% 14% 28% 11% 3	4659
	21st to end	Day	31% 8% 11% 23% 22% 5%	4799
August	1st to 10th	Day	42% 8% 13% 28% 9% 1	4384
	11th to 20th	Day	38% 10% 21% 23% 7% 1	4192
	21st to end	Day	34% 7% 19% 29% 9% 2	4520
September	1st to 10th	Day	38% 7% 16% 23% 13% 3	2325
	11th to 20th	Day	40% 7% 16% 24% 11% 2	2114
	21st to end	Day	37% 9% 18% 23% 11% 3	2090
October	1st to 10th	Day	34% 7% 17% 33% 9% 1	3386
	11th to 20th	Day	35% 8% 21% 21% 12% 3	2842
	21st to end	Day	36% 5% 12% 31% 13% 1	3101
November	1st to 10th	Day	44% 10% 14% 20% 11% 1	1625
	11th to 20th	Day	34% 9% 21% 23% 11% 2	1387
	21st to end	Day	38% 9% 19% 22% 8% 4	1330
December	1st to 10th	Day	39% 10% 16% 18% 14% 2	1330
	11th to 20th	Day	42% 11% 16% 20% 10% 2	1684
	21st to end	Day	34% 8% 11% 23% 17% 7%	2442
January	1st to 10th	Night	45% 12% 16% 17% 8% 2	4726
	11th to 20th	Night	41% 8% 13% 17% 14% 7%	4672
	21st to end	Night	38% 11% 19% 21% 10% 1	4862
February	1st to 10th	Night	42% 10% 15% 19% 11% 3	2660
	11th to 20th	Night	44% 9% 17% 17% 11% 2	2464
	21st to end	Night	45% 6% 12% 22% 13% 2	1885
March	1st to 10th	Night	43% 9% 15% 19% 13% 1	3736
	11th to 20th	Night	28% 10% 21% 25% 15% 1	3589
	21st to end	Night	54% 8% 14% 17% 7% 1	3684
April	1st to 10th	Night	48% 8% 15% 18% 10% 1	1880
	11th to 20th	Night	50% 7% 15% 19% 9% 1	1691
	21st to end	Night	46% 10% 15% 20% 7% 2	1710
May	1st to 10th	Night	54% 8% 12% 21% 5%	2570
	11th to 20th	Night	42% 10% 13% 29% 6%	2199
	21st to end	Night	46% 10% 15% 21% 8%	2414
June	1st to 10th	Night	47% 9% 15% 20% 9% 1	1330
	11th to 20th	Night	52% 9% 14% 15% 9% 2	1330
	21st to end	Night	35% 12% 18% 25% 8% 2	1330
July	1st to 10th	Night	34% 7% 13% 25% 15% 7%	2185
	11th to 20th	Night	24% 6% 22% 30% 12% 5%	2178
	21st to end	Night	25% 5% 12% 35% 20% 3	2511
August	1st to 10th	Night	35% 7% 15% 32% 11%	2521
	11th to 20th	Night	30% 8% 28% 27% 7%	2707
	21st to end	Night	29% 5% 24% 30% 11% 1	3146
September	1st to 10th	Night	32% 7% 18% 26% 14% 3	1852
	11th to 20th	Night	39% 6% 15% 25% 11% 4	2066
	21st to end	Night	34% 6% 18% 27% 13% 2	2090
October	1st to 10th	Night	32% 7% 16% 27% 15% 3	3590
	11th to 20th	Night	30% 7% 18% 31% 12% 1	4086
	21st to end	Night	35% 6% 14% 32% 13%	4457
November	1st to 10th	Night	42% 9% 15% 21% 11% 2	2535
	11th to 20th	Night	33% 10% 20% 23% 13% 1	2792
	21st to end	Night	38% 8% 20% 21% 9% 4	2850
December	1st to 10th	Night	40% 9% 14% 21% 11% 4	2850
	11th to 20th	Night	40% 14% 18% 19% 8% 1	3507
	21st to end	Night	35% 9% 15% 22% 13% 6%	5214

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	9% 13% 37% 26% 11% 4	180
	11th to 20th	Day	6% 14% 43% 27% 8% 2	180
	21st to end	Day	8% 24% 40% 18% 9% 3	198
February	1st to 10th	Day	14% 22% 36% 19% 5% 4	180
	11th to 20th	Day	10% 20% 37% 27% 6%	240
	21st to end	Day	9% 23% 34% 24% 8% 1	377
March	1st to 10th	Day	12% 24% 37% 19% 7% 2	460
	11th to 20th	Day	11% 24% 37% 20% 6% 2	460
	21st to end	Day	14% 25% 33% 18% 7% 2	506
April	1st to 10th	Day	18% 23% 37% 17% 4 1	460
	11th to 20th	Day	19% 20% 33% 19% 8% 1	452
	21st to end	Day	20% 23% 33% 15% 8% 1	460
May	1st to 10th	Day	20% 21% 26% 23% 9% 1	468
	11th to 20th	Day	19% 12% 25% 29% 13% 2	675
	21st to end	Day	24% 12% 22% 28% 12% 2	734
June	1st to 10th	Day	22% 15% 33% 21% 9% 1	680
	11th to 20th	Day	28% 16% 26% 20% 8% 2	680
	21st to end	Day	15% 12% 28% 27% 14% 3	680
July	1st to 10th	Day	14% 10% 29% 28% 17% 3	671
	11th to 20th	Day	14% 14% 28% 28% 14% 2	668
	21st to end	Day	9% 13% 31% 30% 13% 3	632
August	1st to 10th	Day	12% 13% 33% 31% 10% 2	487
	11th to 20th	Day	10% 11% 35% 28% 11% 3	477
	21st to end	Day	14% 14% 34% 26% 11% 1	539
September	1st to 10th	Day	18% 17% 33% 20% 10% 2	490
	11th to 20th	Day	19% 15% 30% 28% 6% 2	490
	21st to end	Day	19% 25% 28% 20% 6% 1	490
October	1st to 10th	Day	17% 17% 32% 21% 10% 3	443
	11th to 20th	Day	15% 19% 33% 22% 10% 1	300
	21st to end	Day	16% 22% 37% 18% 6% 2	330
November	1st to 10th	Day	13% 22% 38% 20% 5% 2	282
	11th to 20th	Day	16% 22% 43% 14% 4	207
	21st to end	Day	12% 23% 36% 16% 10% 4	180
December	1st to 10th	Day	8% 17% 45% 20% 8% 2	180
	11th to 20th	Day	11% 22% 42% 19% 5% 1	180
	21st to end	Day	8% 13% 39% 29% 9% 3	198
January	1st to 10th	Night	11% 19% 43% 20% 7% 1	950
	11th to 20th	Night	8% 18% 45% 23% 5% 1	908
	21st to end	Night	11% 19% 41% 22% 7%	836
February	1st to 10th	Night	8% 17% 38% 24% 11% 3	760
	11th to 20th	Night	8% 17% 41% 25% 9% 1	744
	21st to end	Night	5% 16% 38% 27% 12% 2	628
March	1st to 10th	Night	5% 18% 42% 25% 9% 1	760
	11th to 20th	Night	8% 16% 42% 25% 8% 1	760
	21st to end	Night	8% 13% 36% 31% 10% 2	836
April	1st to 10th	Night	12% 13% 37% 27% 10% 1	740
	11th to 20th	Night	12% 15% 37% 27% 10%	563
	21st to end	Night	16% 15% 32% 28% 9%	570
May	1st to 10th	Night	18% 13% 23% 33% 12% 1	415
	11th to 20th	Night	11% 7% 30% 34% 16% 1	374
	21st to end	Night	20% 9% 22% 30% 17% 1	411
June	1st to 10th	Night	21% 9% 28% 28% 12% 2	380
	11th to 20th	Night	23% 8% 27% 27% 13% 1	380
	21st to end	Night	11% 8% 21% 34% 23% 2	380
July	1st to 10th	Night	12% 4 20% 42% 22%	370
	11th to 20th	Night	13% 5% 26% 35% 18% 2	368
	21st to end	Night	7% 6% 21% 41% 22% 3	416
August	1st to 10th	Night	11% 3 17% 36% 31% 2	378
	11th to 20th	Night	12% 5% 19% 40% 23% 2	484
	21st to end	Night	12% 7% 26% 39% 16% 1	627
September	1st to 10th	Night	16% 8% 26% 32% 16% 3	712
	11th to 20th	Night	18% 8% 24% 32% 15% 3	760
	21st to end	Night	13% 14% 34% 28% 10% 2	760
October	1st to 10th	Night	13% 11% 35% 29% 11% 1	760
	11th to 20th	Night	11% 13% 39% 28% 9% 1	760
	21st to end	Night	12% 16% 41% 26% 5% 1	836
November	1st to 10th	Night	11% 19% 43% 20% 6% 1	826
	11th to 20th	Night	11% 23% 43% 19% 3 1	950
	21st to end	Night	8% 21% 43% 20% 6% 1	950
December	1st to 10th	Night	8% 18% 42% 23% 8% 1	950
	11th to 20th	Night	7% 18% 44% 24% 7% 1	950
	21st to end	Night	6% 18% 42% 24% 9% 1	1045

Page generated at 2024-11-03 00:11:25. Version ac07

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