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ILI Nearby Nowcast

This is the documentation of the API for accessing the ILI Nearby (nowcast) endpoint of the Delphi’s epidemiological data.

General topics not specific to any particular endpoint are discussed in the API overview. Such topics include: contributing, citing, and data licensing.

ILI Nearby Data

A nowcast of U.S. national, regional, and state-level (weighted) %ILI, available seven days (regionally) or five days (state-level) before the first ILINet report for the corresponding week.

* Data is usually released on Friday and updated on Sunday and Monday


The base URL is:

See this documentation for details on specifying epiweeks, dates, and lists.



Parameter Description Type
epiweeks epiweeks list of epiweeks
locations locations list of region/state labels


Field Description Type
result result code: 1 = success, 2 = too many results, -2 = no results integer
epidata list of results array of objects
epidata[].location   string
epidata[].epiweek   integer
epidata[].value   float
epidata[].std   float
message success or error message string

Example URLs

ILI Nearby on 2020w01 (national)

  "result": 1,
  "epidata": [
      "location": "nat",
      "epiweek": 202001,
      "value": 6.08239,
      "std": 0.12595
  "message": "success"

Code Samples

Libraries are available for JavaScript, Python, and R. The following samples show how to import the library and fetch national ILI Nearby data for epiweeks 201940 and 202001-202010 (11 weeks total).

JavaScript (in a web browser)

<!-- Imports -->
<script src="delphi_epidata.js"></script>
<!-- Fetch data -->
  EpidataAsync.nowcast('nat', [201940, EpidataAsync.range(202001, 202010)]).then((res) => {
    console.log(res.result, res.message, res.epidata != null ? res.epidata.length : 0);


Optionally install the package using pip(env):

pip install delphi-epidata

Otherwise, place from this repo next to your python script.

# Import
from delphi_epidata import Epidata
# Fetch data
res = Epidata.nowcast(['nat'], [201940, Epidata.range(202001, 202010)])
print(res['result'], res['message'], len(res['epidata']))


# Import
# Fetch data
res <- Epidata$nowcast(list('nat'), list(201940, Epidata$range(202001, 202010)))
cat(paste(res$result, res$message, length(res$epidata), "\n"))