Lodi
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lodi clear sky chart from 2005-11-05 to 2017-09-24.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
71%
15335
30%
46966
27%
15299
74%
15299
46%
23980

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
62%
716
19%
2443
20%
716
65%
716
31%
1399
January16th to endNight
61%
768
24%
2496
25%
768
64%
768
29%
1499
February1st to 15thNight
59%
696
24%
2267
25%
696
63%
696
29%
1351
February16th to endNight
60%
632
26%
1895
25%
632
64%
632
32%
1147
March1st to 15thNight
57%
720
19%
2049
18%
720
60%
720
31%
1290
March16th to endNight
58%
768
23%
2061
18%
768
62%
768
35%
1266
April1st to 15thNight
57%
719
24%
1799
13%
719
61%
719
37%
1130
April16th to endNight
64%
720
26%
1800
13%
720
68%
720
52%
991
May1st to 15thNight
74%
603
31%
1683
21%
603
77%
603
63%
784
May16th to endNight
74%
374
31%
1496
33%
374
80%
374
54%
562
June1st to 15thNight
76%
360
30%
1440
33%
360
83%
360
56%
529
June16th to endNight
87%
360
38%
1440
49%
360
91%
360
73%
448
July1st to 15thNight
94%
340
37%
1360
48%
340
95%
340
77%
408
July16th to endNight
91%
531
39%
1560
36%
498
92%
498
74%
605
August1st to 15thNight
92%
580
40%
1653
31%
577
92%
577
78%
663
August16th to endNight
90%
764
44%
1910
29%
764
91%
764
83%
842
September1st to 15thNight
90%
720
43%
1800
30%
720
92%
720
84%
797
September16th to endNight
84%
692
47%
1874
40%
692
88%
692
75%
822
October1st to 15thNight
77%
660
33%
1980
33%
660
83%
660
54%
934
October16th to endNight
77%
704
36%
2112
38%
704
81%
704
54%
1003
November1st to 15thNight
73%
700
31%
2234
32%
700
76%
700
47%
1100
November16th to endNight
67%
720
26%
2406
27%
720
70%
720
37%
1281
December1st to 15thNight
61%
720
21%
2520
21%
720
66%
720
27%
1506
December16th to endNight
53%
768
21%
2688
20%
768
58%
768
25%
1623

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 ForecastData
Points
Cloud CoverDay
7%312212335%64%
47965
Night
9%212212335%64%
47151
TransparencyDay
23%38%20%24%19%
47648
Night
23%39%20%24%18%
46967
SeeingDay
8%415%27%29%14%
5942
Night
9%211%38%33%5%
15349

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
17%6%34423436%43%
1492
16th to endDay
17%8%34434336%41%
1728
February1st to 15thDay
18%425%434336%42%
1596
16th to endDay
17%6%24324347%43%
1579
March1st to 15thDay
14%5%244245%7%7%40%
1908
16th to endDay
12%5%244245%48%44%
2163
April1st to 15thDay
13%5%24423448%46%
2149
16th to endDay
7%212213346%64%
2160
May1st to 15thDay
3212211235%73%
2263
16th to endDay
432113345%67%
2615
June1st to 15thDay
3312212335%72%
2520
16th to endDay
11122385%
2520
July1st to 15thDay
111388%
2520
16th to endDay
111112385%
2499
August1st to 15thDay
1111111386%
2298
16th to endDay
11112485%
2292
September1st to 15thDay
11113385%
2160
16th to endDay
32211123378%
1941
October1st to 15thDay
412212346%70%
1650
16th to endDay
7%31331233464%
1760
November1st to 15thDay
8%32332345%7%55%
1625
16th to endDay
12%7%23423446%48%
1551
December1st to 15thDay
16%7%36%5%14336%40%
1440
16th to endDay
19%6%35%423347%39%
1536
January1st to 15thNight
14%42432335%7%49%
2443
16th to endNight
15%424323347%48%
2496
February1st to 15thNight
16%423323448%46%
2256
16th to endNight
16%323323345%50%
1895
March1st to 15thNight
15%424423336%48%
2049
16th to endNight
12%413413436%53%
2061
April1st to 15thNight
11%32332445%7%50%
1799
16th to endNight
6%212213346%65%
1800
May1st to 15thNight
312112326%73%
1683
16th to endNight
312111236%74%
1496
June1st to 15thNight
2111111325%77%
1440
16th to endNight
1111386%
1440
July1st to 15thNight
1111189%
1440
16th to endNight
1112112283%
1667
August1st to 15thNight
1111286%
1662
16th to endNight
1111486%
1910
September1st to 15thNight
1122386%
1800
16th to endNight
1111122482%
1874
October1st to 15thNight
5%11222436%69%
1980
16th to endNight
5%212212345%68%
2112
November1st to 15thNight
9%31221347%63%
2234
16th to endNight
11%313323236%57%
2406
December1st to 15thNight
16%413414347%47%
2520
16th to endNight
20%5%24313346%46%
2688

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
43%5%13%16%18%2
1492
16th to endDay
46%48%17%16%6%
1728
February1st to 15thDay
43%5%9%24%13%3
1596
16th to endDay
41%5%10%26%13%2
1579
March1st to 15thDay
38%7%12%21%15%4
1908
16th to endDay
37%7%15%19%16%3
2163
April1st to 15thDay
36%5%12%24%16%4
2149
16th to endDay
21%312%27%26%7%
2160
May1st to 15thDay
14%38%28%35%10%
2263
16th to endDay
17%5%10%29%26%10%
2619
June1st to 15thDay
15%49%24%25%21%
2520
16th to endDay
5%1315%35%37%
2520
July1st to 15thDay
428%25%57%
2371
16th to endDay
6%138%25%54%
2343
August1st to 15thDay
7%211%31%47%
2282
16th to endDay
6%212%36%40%
2292
September1st to 15thDay
6%1314%34%39%
2160
16th to endDay
11%15%22%35%23%
1941
October1st to 15thDay
14%48%24%27%20%
1650
16th to endDay
23%49%23%28%11%
1760
November1st to 15thDay
28%5%12%29%19%3
1625
16th to endDay
37%5%12%24%16%3
1551
December1st to 15thDay
47%311%19%14%3
1440
16th to endDay
46%412%17%14%4
1536
January1st to 15thNight
34%413%23%17%6%
2443
16th to endNight
36%5%11%17%16%12%
2496
February1st to 15thNight
36%410%23%17%6%
2267
16th to endNight
35%411%25%19%3
1895
March1st to 15thNight
38%411%19%17%7%
2049
16th to endNight
33%5%11%22%20%7%
2061
April1st to 15thNight
32%6%12%23%18%7%
1799
16th to endNight
21%414%22%26%10%
1800
May1st to 15thNight
13%39%24%32%16%
1684
16th to endNight
13%312%33%25%11%
1496
June1st to 15thNight
11%39%26%27%20%
1440
16th to endNight
5%2314%32%41%
1440
July1st to 15thNight
5%117%24%59%
1360
16th to endNight
8%137%24%53%
1560
August1st to 15thNight
6%1113%26%49%
1653
16th to endNight
5%1210%34%44%
1910
September1st to 15thNight
5%1412%33%42%
1800
16th to endNight
8%2322%36%26%
1874
October1st to 15thNight
16%38%23%26%21%
1980
16th to endNight
18%38%23%27%18%
2112
November1st to 15thNight
22%312%28%25%8%
2234
16th to endNight
28%49%24%26%6%
2406
December1st to 15thNight
38%411%20%18%6%
2520
16th to endNight
39%5%12%18%17%6%
2688

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
25%414%25%19%12%
120
16th to endDay
19%416%21%17%20%
256
February1st to 15thDay
21%413%18%25%17%
240
16th to endDay
19%8%15%21%21%13%
238
March1st to 15thDay
19%7%20%17%21%14%
270
16th to endDay
17%8%20%22%21%9%
288
April1st to 15thDay
15%12%21%24%16%8%
269
16th to endDay
10%9%22%25%18%12%
270
May1st to 15thDay
4425%31%25%8%
288
16th to endDay
6%5%17%26%26%16%
330
June1st to 15thDay
5%5%20%35%26%6%
315
16th to endDay
213%33%36%13%
315
July1st to 15thDay
10%30%46%11%
305
16th to endDay
8%35%40%14%
327
August1st to 15thDay
214%34%38%9%
315
16th to endDay
8%33%40%16%
332
September1st to 15thDay
9%31%41%15%
315
16th to endDay
2314%28%28%22%
288
October1st to 15thDay
5%415%29%27%17%
255
16th to endDay
11%411%20%31%19%
272
November1st to 15thDay
9%36%20%30%29%
131
16th to endDay
11%213%37%30%3
79
December1st to 15thDay
28%6%16%23%23%1
60
16th to endDay
12%317%25%31%10%
64
January1st to 15thNight
16%110%34%29%7%
720
16th to endNight
17%210%33%28%7%
768
February1st to 15thNight
17%211%34%28%4
704
16th to endNight
16%412%40%21%4
632
March1st to 15thNight
15%314%32%29%4
720
16th to endNight
14%316%38%25%1
768
April1st to 15thNight
11%420%38%23%2
719
16th to endNight
7%220%36%28%3
720
May1st to 15thNight
317%43%29%5%
604
16th to endNight
4116%35%40%2
375
June1st to 15thNight
3114%50%30%
360
16th to endNight
19%49%37%2
360
July1st to 15thNight
344%51%1
340
16th to endNight
1336%52%5%
531
August1st to 15thNight
1340%50%3
580
16th to endNight
16%43%45%3
764
September1st to 15thNight
6%37%49%4
720
16th to endNight
110%37%40%8%
692
October1st to 15thNight
5%310%40%31%8%
660
16th to endNight
5%29%33%38%10%
704
November1st to 15thNight
9%19%39%34%6%
700
16th to endNight
12%111%39%29%6%
720
December1st to 15thNight
17%310%38%24%5%
720
16th to endNight
20%5%13%33%24%2
768
Page generated at 2017-09-25 06:02:25. Version ac04

Copyright 2017 A. Danko


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