Tuesday, February 16, 2010

Disneyland and the Weather

Yeah, yeah, everybody always talks about the weather, but nobody ever does anything about it. I'm here to change that: I'm putting it in the thesaurus. For some time I had contemplated enhancing my day-by-day history of the Resort with daily weather data, but it seemed a daunting task. Since I just had an eleven-day, weather-induced weekend, I looked into it further and came up with a plan.

In a perfect world, the data I draw on would be an unbroken climate record from 1955 to the present at a station in Disneyland (perhaps in the Central Plaza). The only thermometer I can think of at the Park is at the entrance to Coke Corner, but its unrecorded temperatures mean it's pretty much worthless for my purposes. It would be interesting to know if Disneyland did record climate information; I haven't found anything to suggest that they share it, if they do.

So, the next best solution is to find a nearby climate station whose weather is similar to Disneyland. Luckily, there is indeed such a reporting station: the Santa Ana Fire Station, part of the National Weather Service (NWS) Cooperative Observer Program. The Fire Station at 120 West Walnut St., Santa Ana (NWS ID: STAC1) is close to Disneyland (5.5 miles away), about thirty feet lower in elevation (not much), is only about a mile closer to the ocean, and has records dating to the early 20th century.

However, no climate station of any reporting length has perfect records, so I had to search for backup stations for when the Fire Station didn't report data (about 500 days over the course of nearly 55 years). In ranked order in terms of similarity to Disneyland's weather, I chose:
  • Tustin Irvine Ranch: records until 7/31/2003, when it was replaced by the station named Irvine Ranch. It tended to run a few degrees warmer than the Santa Ana Fire Station during the day and usually more than a few degrees cooler at night. Casual analysis showed it may have received more precipitation, as well. At 235 feet in elevation, it's not too much higher than Disneyland.
  • Anaheim: This might seem like a more natural choice for Disneyland, but it only began operation on August 1, 1989. While the station name is Anaheim, it is actually in Atwood, north of CA-91 and east of CA-57; its further inland location means it will generally run warmer than the Santa Ana Fire Station (and Disneyland).
  • Irvine Ranch: This station succeeded the Tustin Irvine Ranch station as of 8/1/2003, but is much higher in elevation (540 feet). My assumption is that the old Irvine Ranch station was done in by suburbanization.
So, within the thesaurus will be daily data (when available) for each of the above stations from July 1, 1955 to the present. Even with all that data, there were still 29 dates for which I had no data. I used Long Beach Daugherty Field (LGB) as my last resort. It's quite a bit closer to the ocean and not as close to Disneyland as I would like, but it has a lengthy reporting record that filled in when necessary. Unlike the other stations above, I only included LGB information for those days with otherwise missing data.

I make no representation that this pastiche is a true climate record for Disneyland, but it's close enough for my purposes. I think the weather information together with Park hours gives color to the daily history. Torrential rains and mid 50s is a lot different than high 70s and no precipitation, right? To show what I've done, let's take a look at a few dates in the summer of 1955. In The "E" Ticket #43 (Fall 2005), Ron Dominguez said, "In August of 1955 we had a terrible heat spell and attendance took a nose-dive. That kind of worried a lot of people." (I think this is also in Randy Bright's Disneyland: Inside Story, among other places.) For eight days, from August 31 to September 7, the high temperature was 97 degrees or higher, with a peak of 108 degrees on September 1. (The reading is among the highest in my Disneyland climate record.) This is what the record looks like for September 1, 1955:

  • DATE: 0901d September 1
  • DAY: THU Thursday
  • DLHR: 1022 10 AM - 10 PM
  • DLHRNOTE: 10 AM - 10 PM
  • ETY: DATE Date
  • PRECIP: PRECIP-NO Day without Precipitation
  • TEMPMAX: 108°F(h) 108°F
  • TEMPMEAN: 89.5°F(m) 89.5°F
  • TEMPMIN: 71°F(l) 71°F
  • WX: Santa Ana Fire Station (STAC1): Obs Hour Temp: 6PM / High Temp: 108°F / Low Temp: 71°F / Mean Temp: 89.5°F
    Obs Hour Precip: 6PM / Precip: 0 in.
    CDD: 24.5 / HDD: 0 / GDD: 39.5

    Tustin Irvine Ranch (TVEC1): Obs Hour Temp: 6PM / High Temp: 110°F / Low Temp: 66°F / Mean Temp: 88°F
    Obs Hour Precip: 6PM / Precip: 0 in.
    CDD: 23 / HDD: 0 / GDD: 38
  • BT: 1955-09
As I mentioned earlier and you can see here, the Tustin Irvine Ranch station is a touch warmer during the day and several degrees cooler at night than the Santa Ana Fire Station. And yes, I am tracking which days had precipitation, but it's not exactly perfect. The late afternoon reporting time means that that's precipitation from the 24-hour period 6 PM-6 PM--not the 24 hours of September 1. If it rained after 6 PM on September 1, it would be reported with the September 2 numbers. So, it's not an exact indication of all rainy days, but it can reveal wetter patterns (such as this one from 1978) and at least get one in the ballpark of rainy days. For the record, from July 1, 1955 to November 30, 2009 (the latest date for which quality controlled climate data is available), my climate record reveals 2,120 days with precipitation.